Well, for me, it's been 33 years and counting...
to be honest, it hasn't been a difficult adjustment for me, because it wasn't as severe for the first number of years, but got worse as time went on. Another factor for me is that I had worked with physically disabled adults prior to my accident and knew what catheters and incontinence products and things like braces and hoyers (?) are for- they're ALL medical devices, so when I had a head injury, I figured it was all going to go away- in six months... (yeah, I believed that- until the seventh month) Anyway, I had too many other things to worry about, including vision problems no one could diagnose or treat, a very severely broken ankle, and insane headaches, so my need to wear protective underwear wasn't the most significant problem. In fact, it was a solution. I eventually accepted that my urinary incontinence would probably not resolve itself and the stigma of wearing or purchasing adult products was behind me, so, now that it is as bad as it is, well, that's just life, I guess. And really, it's only as big an issue as I make it. But... I am still surprised when I stop to think about it, because I REALLY would never have guessed that I'd be dealing with this. It's still better than losing my sight or one of my feet.
Sorry, that got long-winded. To sum it up, and there are others on here who have said similar things- once you get past the stigma, life does get better.