Honestly, I don't really learn anything specific in game jams, it's more of a slow buildup of experience.
But I guess if there had to be something, I guess my takeaway is this: it's OK to interpret themes in an unconventional way.
Previously, in game jams, if there were themes, I'd make my game very closely tethered to the most literal interpretation of that theme. But this time, I was a bit more abstract with my connection, and most people seemed to enjoy the unique take on "diving deeper". Whether my game would've been better with, you know, a more close, obvious or literal tether to the theme, we'll ever know, but I tried something different and it still made for a solid entry.
So if I have a less obvious interpretation of a theme, no matter how abstract, no matter how unfitting it might seem at a first glance, I might be more inclined to do it in the name of standing out. But I'm not gonna make, like, a game where you play in a housefire when the theme's "car wash" because that's TOO far-fetched.