Continuously learning new pieces is a commitment and requires a lot of patience, but I'm hoping the pay off in the long run will be worth it.
That's a very magnanimous sentiment, and I agree.
For the OP's question? Maybe it's my temperament or capability, but I'm "learning" dozens of pieces at any given time. Pieces that I've culled from many times more just reading through at the keyboard.
And a certain amount of maintenance for sets that were previously "acquired." No, I don't go back to playing the Pathétique or Op. 27/2, but things that still remain of interest.
However, I can certainly be called a hack or a punter, but continually adding new pieces, from repeated reading at the keyboard, is not a bad thing at all, IMHO. I'm still stuck on the last fifty or so bars of any number of Bach fugues, at tempo. The Chrom.Fant.Fug.d.min. for example. Which, to me, is kind of difficult to read at tempo (the toccata/fantasy portions, at least: kind of odd scalar figures to figure out in real time off the page....the fugue is somewhat straightforward, but also extremely odd in ways I don't feel like grabbing the score and detailing).
But at that point, a point of stagnation, I'd rather sit down and analyze away from the keyboard, to what extent I'm able.
Yeah, maybe two dozen pieces I'd say I'm "learning," plus half that number I'm learning and can play with the score, and plus half that again are maintenance of sets already learned.
And 200% finding new (to me) music and reading it at the keyboard. Including violin concerti (FWIW, I cannot stand the violin), string quartets, whatever. If it exists, and if it's interesting, I'll play it.
But, no, I don't get paid to perform classical piano, so while I've adopted a somewhat professional attitude to the discipline, and adhere to my schedule and lists somewhat rigorously, it's more for my own benefit. There is some cross-over to paying jobs, but, honestly, these days, finding a good music performance job is not what it used to be: free beer and the attention of many <insert desired sex> gets pretty old after a while, at least compared to getting compensated in cash.
Becoming a better musician, though, never gets old.
/* EDIT I guess the OP is some kind of student or something trying to pass an exam. Well, in that case, you have to focus. But unless you're a teacher/adjunct professor/professor, or one of the very few well paid performers, it doesn't matter, really. Pay for performance is bollocks, I'd say. Any money as a professional is near the console, or sent in as a hard drive stem to the mixer. Live music is dead.
Yes, I'll say it: live performance of classical music is done. It's as done as billiards, snooker, or pool are as a sport. Even opera, despite many recent magnificent attempts.
So, why? Well, I play pool, recreationally, sometimes pretty good. Same with the piano and the Hammond organ. Occasionally I get a few bucks swung my way.
Teaching is the only reason to "master" a piece or a set of pieces. Go where the money is.
I think classical music is now what jazz music used to be in fern bars and private parties. Not good. */