I agree that in order to learn something, it is best to limit yourself so that you are aware fully what the system can do, and make the best out of it.
Having said that, in my case I was 'seeing' things in a wideangle perspective and my 'normal' lens is a 20mm (in any filmformat). Makes you go closer to the subject (and you need to place a subject near the lens or else it is boring), something I like to do anyway when photographing people. If the subject is too far, I just don't take the picture....just enjoy seeing it.
If you think you like the 50mm prespective, use that to the fullest! If you like anything else, the same!
More importantly: develop your own style, doesn't matter if you need to copy someone elses style first, but in the end, you need to stand out! Don't follow trends or the crowd.......
Hong Sien