If there's just one advice I could give my younger self, it'd be to keep a diary, and to do so consistently throughout my life, not just when I feel like it.
I kinda do both with a Bamboo Folio smartpad (hand notes that you can download as SVG data), but I think either way works fine. Whatever works better for you or is more convenient to you, really.
Just make sure whatever you pick can actually be performed as some form of a daily ritual. So if you need your desktop PC, it wouldn't work during travels. Oh, that reminds me: especially keep a diary during your travels!