Crazy? No. But you are correct that it's a major decision and the long-term (20-30 year... 40-year I hope) data simply don't exist (at least to my knowledge).
I'll soon enter my 4th week post op, and I still have those nagging questions, but I can also tell you I am amazed at what I can do with my hip now that I couldn't before. Sure, the surgical discomfort is still there (and I'm not yet allowed to violate the dreaded "hip precautions"), but I can now raise my leg to nearly 90 degrees. Four weeks ago I could hardly raise my leg in the front. So I have some hope that I made the right decision at the right time. I could have toughed it out a while longer, I suppose, but I wanted to return to my active lifestyle; I wanted to climb hills with my kids; I wanted to walk through the Magic Kingdom and not be the one having to constantly stop and sit (or not sit if the seat was uncomfortable).