Essentially every yoga injury that I've had has been the result of one or more of the following:
1. Got in a hurry and moved too fast
2. Wasn't paying attention
3. Was paying attention, knew I shouldn't do something, and did it anyway
I'm going through a phase of little tweaks in asana practice lately...I consider it my body's way of getting my attention. The newest tweak is a funny sort of strain on the back of the right knee. I attribute this one to overzealous flinging of the legs when jumping through. I suspect I hyper extended it and it is pushing back. This one belongs in the "got in a hurry and moved too fast" category.
Asana practice is such a mirror for the rest of my life. I'd say most of the life events where I have the feeling of wanting to back up and try again are also a result of the above three situations. I'd like to think my overall attention has improved over the years...there are less yoga tweaks than early on and I have the sense that there are less "life tweaks" too, but that's harder to say for sure.
The most interesting part for me is that none of the strains or aches of yoga or life have ever been all bad. Nothing has ever been all black or all white...really just different roads to the same place. I can't often see that in the moment though.