No Means No

I am starting to tell Brock "no" sometimes. He doesn't do much that I don't want him to do, but I figure it's good to start teaching him the concept. So when I was eating my breakfast the other day and he wanted to get into my cereal, I kept telling him "no". Except it came across more as a funny game and he just kept laughing at me...I take full responsibility for this. Maybe he thought it sounded funny the way I said it. Maybe he thinks his smile will get him whatever he wants in life. I'll use a stern mommy voice next time and try not to laugh.