Getting a little sore

Even after countless workouts I found a way to get really sore! On Saturday morning I was all inspired to workout. It was leg day and I felt really good. I have done this workout I don't know how many times. Anyhow, I changed it up a bit by doing every exercise with perfect form and until I couldn't do anymore reps. Deep squats, holding movements a little longer, etc. Sunday morning I woke up with sore legs, not bad, but sore, I was a little suprised. Yesterday my legs were so sore I could hardly walk! Talk about sore, geeze, not even sure what up with that, the workout must have worked well. Today, Tuesday, they are still sore but better, should even be able to go for a run tomorrow. Great workout, but paying the price, don't seem to heal up as quickly as I used to :)