Is it really possible to be really good with only one hand?

[Poisoncage]

I play with my right hand; three fingers, and mostly Standard-Very Difficult songs. Yes, they are getting much harder, but that is only to be expected. Doing Up-Downs are not as difficult now as before (getting used to it) but staircases are much, much harder then ever before. I was thinking of trying another way to play, however, after trying a spread I decided I like one-handed better. It's a lot more challenging for me, and I'm not one to back down from challenges so easily. XD
nya~!