I was once told that a reason why people dead with re-spraining a ton is because their ankle is never really allowed to heal and strengthen to the same extent as their other ankle.
I have that problem with my right ankle right now. Never took it to physio-- I still need to stretch it a ****-ton before every basketball or soccer game, cuz it's still stiff/hurts. It sucked, I actually went through 20 years of athletics never spraining anything (I had superb ankles) but then I just really ****ed it up last summer.
You probably don't do enough re-strengthing and rehab on it either, right?