In the 7+ years of running and 4+ year of running 100 milers I've been relatively injury and pain free. Issues have been primarily focused on sore muscles post race and a few tweaks here and there. I didn't really think anything about it when my hamstring started giving me issues in the fall. Eh - it would go away, I could run through it, and it wasn't a big deal. But it didn't go away, and I could run through it but had to grin and bear it. It didn't initially seem like a big deal, but ended up taking more of a toll than a realized.
Nothing I did to fix it worked. I couldn't stretch enough - it was always tight. Rubbing the back of my leg was like rubbing concrete. I had my legs massaged and it left a massive bruise where there was scar tissue. Epsom salt, compression shorts, a thigh sleeve - I tried everything. I tried everything I could physically do.
What I didn't do is work on the mental side. I didn't accept that I had an injury that would not heal without rest. I didn't accept that I had an injury that wouldn't heal without strength training, patience, and discipline. I didn't accept that sometimes the will and mind are stronger than the body can bear.
The hamstring isn't 100% fixed. Better, but not fixed. While I'm still working on the physical side, I'm much improved on the mental side - ready to work to get better. To not force the issue. To be patient and ready to go when my body is able.