I was also confused by the OP. But since I like the topic, I'll answer it two ways:
1) I'm sure I somewhat mentioned what I would give to my younger me not long ago (
last Thursday, in fact). I would travel back to the early 2000's and give myself rocksmith 2014 (and the needed drivers for the USB-to-guitar thingy, obviously

). This would also break the space-time continuüm, so I would return to 2018 as someone who actually knows how to play guitar and a millionaire (what? you're saying you WOULDN'T tell your younger me to invest everything in google or that amazon bookstore?

).
Alternatively, I'd go back to the mid nineties and hand out some USB-drives with copies of ubuntu, mint and solus (with source code). That way, perhaps linux would be the de facto standard instead of windows when it came to operating systems.
2) what I want to receive from my older self is...somewhat in the same vein in the sense that I want something I can't predict now. Rocksmith built upon many iterations of widely popular rhythm games (which ensured they got better over time). So I want something that isn't much of a genre now (or at best an almost unknown niche genre) that gets popular, spawns a bunch of clones and sequels, up until one "major" awesome game comes out that pretty much defines this genre. That's the game that I want (erm...assuming my current PC can still run it, of course).
The source code for a perfectly working switch emulator would also be fine, though.
