I pretty often think of the lines:
"And then one day you find
ten years have got behind you.
No one told you when to run,
you missed the starting gun."
from Pink Floyd's Time and imagine a 30-year old, nostalgic me unfulfilled with how things turned out. I use this to motivate myself to make a little bit of time everyday for doing small things like reading, playing the piano, or drawing. Things that require persistent effort. To use my time well, and to make sure I don't fritter and waste the hours in an offhand way.
I've listened to this song probably over a hundred times. But I realised recently that even though I'm only in my 20s, it applies going back in time as well. Ten years have gotten behind me since being 11. What's more, it's not like time's up once you're 30. Or 40, or 50, or 80 (though after that the odds of time being up does dramatically increase). Health-willing, you can always push yourself to learn and do new things.
Half a page of scribbed lines is how to start.