Definitely couldn't have put it off. I was working around the house, lifted something funny, felt a weird kinda tingling pain and thought nothing of it.
Two days later I couldn't sit in a chair or bend over to put my socks on or tie my shoes. Trying to sit normally in a chair was impossible. I had to have my mom put on my socks because I couldnt bend over.
Went to the doctor and after a few x-rays and an MRI was told that I had two herniated discs, one of which was pinching the sciatic nerve in my left leg. Terrible, terrible pain.
After a few weeks of physical therapy, traction, and some medication I began to regain some mobility and flexibility. I'm still not 100% by any means (this originally started in 2007), but I'm a HELL of a lot better than I was. I would be even better if I kept up my gym routine and started doing my stretches again.
Granted it was a freak occurence and could have been avoided had I been more careful, but that holds true for 99% of injuries that require medical care.