Discipline part 2

I have gotten so many responses both through comments and e-mails about my discipline challenges with Lucas. Thank you to everyone that offered kind words of encouragement and advice. I have been thinking a ton about this today. It is -10degrees with wind chill here today so we have been stuck inside trying to stay sane and warm. I have a few things to add after reading y'all's responses and pondering all this in my head today.
I hope I did not make it sound like I have a tyrant on my hands. He is a handful, no doubt, and I am not back-peddling on what I said before. It is all true. I do feel we are at a crucial point for discipline where I need to be consistent and firm. But, he mostly very sweet and loving and is even playing independently and quietly with some new dinos as I write this (which RARELY happens). I think because he is so smart that I often hold him to very high standards of comprehension. I expect that he is fully understanding what I am asking him and that he is choosing his own behaviors over obedience. I don't think this is always true. I think he is testing the boundaries, testing what he will be able to get away with. I think my friend Rachael was so right when she said it is not that he is willfuly disobeying (which I think maybe he is sometimes) but rather learning the limits of his own will versus my requests of him. I often assume that he has learned things that he is still in the process of learning. He still kicks even though I have told him no because he is still disciphering that line between playful cuteness and disobediance. He is after all only 21 months old.
The other thing that occured to me today... yesterday was rough for us (thus the blog post). I was tired, we were all recouping from the holidays and travel. And, I was tense and upset because the Gators were playing so poorly. I was distracted and not giving him my full attention. I think most of his "poor behavior" was probably his attempts to get my attention and his response to my own erratic behaviors. Here I am blaming Lucas for being so disobedient when I probably didn't help the situation at all. Today, he has been so much better. He has my attention, we are playing with his firetruck and puzzles and he is getting stimulated and affirmed. Huge lesson for mommy here.
I still need a consistent clear plan for discipline. A way to set good boundaries and help establish good patterns of behavior. For Lucas and for me. At least no more football for awhile might help.