Hi Sophia
We never stop learning! While we're off topic (sorry everyone) I'll throw in another crucial thing for me, which was learning to understand chords. I've rabbited on about this at length over on PW, but I'll briefly explain again here.
When I play in my band I mostly play from chord charts (which I write out), which might look something like this:
|D9 |Am7 |C C7 |G | etc etc
The space between 2 uprights is a bar. So I know there's a bar of D9 then a bar of Am7, then a bar where C major becomes a C dominant chord and so on.
I spent several years when I was in my early 20s learning to understand what the chord symbols actually mean.
For example the chord Am7 contains the notes A C E G. So if I have to improvise a solo I know those notes will fit, I also know that assorted scales will work as well (depending on the context - i.e. the type of song). But the big learning point for me was understanding the constituent notes that make up chords. Suddenly you have a small vocabulary, you can fall back on when there's no sheet music. There are some chords that I'd have to think about, i.e. advanced Jazz chords with multiple alterations Db13#9b5 for example.
The result of all that work means that I can now instantly voice a lot of chords in either hand in multiple positions without thinking about it. A lot of people learn to voice chords in their LH only. That's a mistake don't do that. Learn them and their inversions in both hands, and spread them playing with both hands.
In the professional ranks of (non-classical) session musicians, chord charts were (and may still be) what a lot of the great studio musicians used when they went to a recording session, whether to record a jingle, a pop song or a record a Jazz session.
And as a side bonus the effort I made has paid off in my reading (great for classical), as I see and read chords in sheet music much faster (because I don't read the individual notes; well at least not consciously). Sure I've mentioned that before on here somewhere.
I'll get me coat!
Cheers