If you hyperextend your knees and elbows, can bend your fingers back more than anyone you know, seem to have joints prone to dislocations, and have a constant desire to "stretch, stretch, stretch", you might be hypermobile. In hypermobile people, collagen is different from non-hypermobile people's collagen, it is weaker making their tissues less able to stabilise the joints. It is typically an inherited condition and there is nothing you have done "wrong" to create this. Moving within a safe range of motion, centrating the joints in the sockets (e.g. hips, shoulders) and strengthening stabiliser muscles is really important if you have very mobile joints to keep you safe and strong.