Well, speaking from my own experience, I was guilty with the same mistake that the thread starter was in now too. However, I came to realise that practicing pieces that are way above my skill level would result in following things:
- "Unfinished piece" syndome, this is very common syndrome among many aspiring pianists, try a very difficult piece, learn it halfway, then stop, in the end never complete a single piece, I know many people that try to learn a Beethoven sonata , but then they could not persevere even to the end of first movement, because they complained it was too long and difficult for them.
- Waste of time, the time spent learning a piece outside realistic skill and musical limit is better spent acquiring real repertoire that i can perform comfortably. Not to mention the stress that arise from encountering enormous technical and musical difficulties. Doing this is the quickest road to nervous breakdown.
These are two most obvious disadvantages of learnin pieces above realistic limit. So to those aspiring pianists out there, you may be hardworkin and progress faster, but do not skip the musical progression that every good pianist go through.
In the end, compete with yourself about making better music, theres no point boasting about how difficult a piece you can play, but if you don't make music, theres no point at all.