I was the same way before, I always warmed up well before my training but I have always been bad about stretching and foam rolling after to keep everything loose.
In my opinion, stretching and prehab are amazing tools to keep your body working correctly. When you let those things go, even though you might be making progress and feeling good, you could be breaking down in certain areas and not know until it gets injured (just like what happened to you).
I know people have busy lives and it is easy to say that you'll get to it later, but after injuring myself and then putting in a stretching regiment I see why I injured myself by not taking care of my body in that way. It is something every lifter (and person in general) should be aware of and make a part of their everyday routine.
Class I Total @ 198: 525/335/600 (1460)
"No citizen has the right to be an amateur in the matter of physical training.... What a disgrace it is for a man to grow old without ever seeing the beauty and strength of which his body is capable."