What about my legs

I can't help but picture the Dave Chappelle skit, when he is Rick James, and he is kicking his dirty feet all over Eddie Murphy's couch, and then Charlie and Eddie come over and beat on his legs till he can't walk.  That is what my workout from last night made me feel like.  So with talking to Kirk about my workout, he had suggested I start my workouts with an explosive exercise, so I took that to heart and decided to do Power Cleans to start out.  Then went well, up until 155.  I was coming up on my 3rd rep, when my left knee kind of gave way, and I almost dropped the weight.  I recovered, and got the weight back on the rack, and moved on to dead lifts.
Steve arrived in time to jump in on the deadlifts with me.  Both Steve and I were both having issues with our lower back yesterday, for different reasons, but it made doing both dead-lifts and squats relatively difficult.  After dead-lifts we moved onto squats.  I finished at 275, and by then, I was completely gassed.  I did do 7 to 8 reps though, so I could have went up to 315, and squeezed out some really good ones, but for some reason, I decided to save what I had left for Bulgarian split squats.  The split squats went pretty good.  I couldn't believe, at 135, how much my "resting" leg would burn during each rep.  It is a tough exercise, mostly because I have only done it one other time.  I was pretty beat after last nights workout, but I was also pretty happy with where we ended up.  I don't think I fully taxed my legs, but I hit them pretty hard.  I do know that I need to take it to another level in order to be successful.  It is the person that can push past the pain and fatigue that wins, and I need to be that person.