Use What You Know
It’s not how much you know but how you use what you know…. … is an idea that very much applies to piano playing. You don’t need a PhD in music theory to successfully play piano. If you learn some of the basic concepts of piano playing (especially the chord method and some improvisation techniques) and get in touch with your own inner musical flow you will be playing wonderful music in no time. Also, the expression less is more applies to piano playing as well…it’s not how complex or advanced the music you play is that reflects your success but rather the feelings of enjoyment and satisfaction you get from what and how you play that counts.