Things I Learned - December 2025
Hello and happy new year. Here is December’s edition of Things I Learned.
Things I Learned
The vast majority of caviar is produced in China. (source)
(Good) King Wenceslas, of Christmas carol fame, was never a king in his lifetime. He was a duke who was posthumously made a king by the Holy Roman Emperor Otto the Great to commemorate his piety, and hence is referred to as a king in song. (source)
Americans who make the median full-time wage ($63,128) are in the top 3% of global incomes. (source)
Almost every car in Turkmenistan is white; it is illegal to have a non-white car in the capital. (source)
Relative to their population, Jews were overrepresented in the US military in World War I by a factor of 1.6. (source)
The reason that, historically, almost all war elephants were male (while female elephants were used for logistics) is not because of their greater aggression, but because a female elephant in battle will typically run from a male. (source)
According to MPAA rules, a single use of the F-word requires a rating of at least a PG-13, while additional uses elevate a movie to an R. (source)
6 percent of America’s school-age children are homeschooled. (source)
The Amish population in the US roughly doubles every 20 years, and (today) is eight times as large as it was in 1970. (source)
May 1 — “international labor day” — is the day of the year when the most people around the world have the day off work (not January 1!). (source)
Today’s 12 graders are now less likely to have had a sip of alcohol in the previous month than the 8th graders of the 1980s. (source)
One horse can generate about 15 horsepower. (source)
In the UK, the majority of individuals die holding more than 60% of their peak lifetime assets (source).
The Los Angeles Dodgers, formerly the Brooklyn Dodgers, got their team name from “Trolley Dodgers”, named after the Brooklyn pedestrians who dodged trolleys in the city as a game of chicken.1 (source)
Draftkings and Fanduels make four times as much profit from online casino games as they do from sports betting. (source)
100% of flights to and from the world’s busiest airport (Dubai) are international. (source)
Men are significantly more likely to be struck by lightning; males account for some 80-90% of all lightning strikes, injuries, and fatalities. (source)
In 2024, the EU made more money from fines of US tech companies (€3.8B) than it did from incomes taxes on public internet tech companies (€3.2B). (h/t)
Things I Liked
This man’s project to train an LLM using only 1800’s London texts.
This guide to data visualization.
My niece, who was born yesterday.
This (blog-appropriate) notebook I received as a birthday gift (take notes!):
On this day in previous editions:
(December 2024) The song “Sweet Caroline”, by Neil Diamond, refers to Caroline Kennedy. (source)
2025 Wrapped
End-of-year reviews (or “2025 wrapped”) are all the rage these days. As someone who likes to quantify things, I have been documenting such personal end-of-year stats for several years now. Continuing the tradition, here is my 2025 in review.
Professionally, 2025 was a bit of a whirlwind for me.
From January - March: I worked for AQR (in Greenwich) as a Quantitative Sports Researcher.
From March-September: I worked for The Economist (in London) as a financial journalist under the Marjorie Deane Fellowship.
From September onwards: I joined Citadel (in NYC) as a Quantitative Researcher.
All the while I was finishing up graduate school (in Chicago). I successfully defended my dissertation in April, received my PhD from the University of Chicago in June, and got my MBA as well (also from the University of Chicago)
So — by the numbers — let’s call it 4 jobs in as many cities; 2 degrees; and 1 single week off in between gigs (Sep 2-7). I won’t say too much about these experiences, in part because I already have to some degree, but I’ll simply note that these jobs aren’t quite as different as you might think. At the end of the day, it’s just taking data and explaining stuff in the world: sometimes it’s a stock price and sometimes it’s a batting average; sometimes the medium is a powerpoint and sometimes a witty article.
Some more of my year in numbers:
Travel: I took 50 flights. I visited 11 countries (USA, UK, Norway, Denmark, Portugal, Belgium, Germany, UAE, Saudi Arabia, India, Egypt) and 7 states. I spent 25 nights in hotels. I took 68 Ubers, 27 Lyfts, 9 Divvy bikes, and 5 Careems.
A total of 2 of these flights were for work.
Writing: I wrote 16 articles for The Economist, 12 blog posts for my personal blog, and 1 dissertation.
Health: I went on 117 runs2, completed 37 indoor cycling (peloton) rides, and did 3 bootcamps. I slept an average of 6 hours and 55 minutes a night.
My gym in London (PureGym) did not have a Peloton, hence the flat range from March - September.
Entertainment: I watched 7 seasons of television and 2 movies in the cinema. I read 6 books (and many econ articles). I played 6,026 games of chess and hit my peak (online) rating of 2253. Note: If you think that’s a lot of chess games (a) it is (b) I almost exclusively play with 1 minute time controls, so can often knock out as many as 40 games in 1 hour3 (c) I typically play when I need to procrastinate (or am otherwise stressed about something).
Miscellaneous: I went to 2 weddings, 2 shivas, and I don’t remember how many birthdays. I made 3 mistakes: one professional, one personal, one financial.
Most of these numbers are improvements over last year’s, and some of the resolutions I had set for last year (pack less, improve my gift giving, do a better job staying in touch with long distance friends and family, etc.) I think I did well on. I did not do as good a job with reading books or writing (non-listicle) blog posts, but given how packed the year turned out to be professionally, I will give myself a pass.
For the coming year I have the same broad goals as last year (reading and writing more; go to more live events, etc) and some minor specific ones.4 But for more important things, I generally ascribe to the advice that you shouldn’t tell people what you’re working towards because it gives a premature sense of satisfaction that you should only get once you’ve completed it. One thing I have been thinking a lot about, however, is David Brooks’s discussion of eulogy vs. resume virtues: “The résumé virtues are the skills you bring to the marketplace. The eulogy virtues are the ones that are talked about at your funeral — whether you were kind, brave, honest or faithful.” Since it was a busy year for my resume, I’d like to work on my eulogy virtues this coming year.
I hope everyone has a happy start to 2026!
I also learned that the Dodgers’ previous team name was the “Brooklyn Bridegrooms”. We just don’t name teams like we used to!
Defined as any indoor or outdoor run ≥ 5km.
For example, I spent more time in the air this year than I did playing chess.
For example: I want to learn how to throw a pot, score a baseball game, checkmate with a bishop and knight, and do an airwalk pull-up.
Surprised by: caviar fact, horse to horse power ratio, old baseball names and that no fact I've told you made it in. Very much support eulogy metrics.
This is excellent writing