Last November, I strained my neck and shoulder just getting out of bed one morning (yup, I'm officially old!). I'm sure it was a "straw that broke the camels back" kind of thing, an injury waiting to happen due to tense shoulders. I was immediately in an excruciating amount of pain and completely out of commission from teaching and practicing yoga for a few days. When I took my first class (post-injury), I quickly learned that I wasn't going to be able to practice in the way I normally do, pushing myself to my edge in most poses, and at least attempting most if not all of the advanced pose variations, arm balances and inversions that my teachers might throw at me. I was forced to modify poses that I wouldn't have (i.e. - stepping back to high plank instead of jumping back into chaturanga dandasana), and practice humility when my ego was begging me to go deeper.
Fast forward 5 months later: I'm on the mend, but I still have recurring pain in my neck and shoulder so I still modify my practice a lot, especially on days where my neck and shoulder are fired up. I also avoid any poses that I know will aggravate my condition, including headstand and shoulder stand. But I am stronger for it. Maybe not physically, but mentally. In the end, Yoga is all about listening to your body, and having an injury might force you to come to that realization sooner than later.
Have you ever injured yourself and had to modify your Yoga Practice because of it? What did you learn about yourself from that experience?