Playing With The Basics
A recurring thing I've seen is that people at the top of their field often continue "playing with the basics" in a surprisingly simple manner. People doing political data science make their own spreadsheets painstakingly collating polling data. People working in macroeconomics have a separate copy of the official statistics on which they run some basic analysis of their own. Finance people pull together quarterly reports of public companies and do some rather straighforward modelling on them.
The common pattern is that it takes some amount of effort, it exposes you to your field (and gets you to interact with the bits and pieces), and it is far simpler, methodologically, than what you'd expect of people at the cutting edge. Here you have a bunch of people coming up with entirely new approaches and models for things, yet this stuff looks like you could start doing it yourself after seeing someone walk through it once or twice. You may not get the same insight from it as an expert when you start out, but the knowledge you need to get started is right there.
It reminds me a bit of how Feynman got over a period of burnout by taking a more playful approach to physics again. Or of the conversations about deliberate practice in knowledge work.