Nothing. No money for investments then or now, which is also why I never kept up enough with stocks, crypto etc. to be able to cheat the market as a one-time time traveller. Plus I have several medical issues (then and now) that remain unsolved mysteries.
Only thing I can think of is using a bigger boot partition when I installed reinstalled Ubuntu from scratch about 5 years ago.
It's mostly just a recent issue that popped up. I'm currently running Ubuntu 20.04 (i.e. version from 2020, there have been two major releases since then) and since I use LUKS, resizing the boot partition is going to be fairly complicated, if I can figure it out at all.