Testing Boundaries

I have to admit I'm not a huge fan of my 4 year-old's boundary checks every day. How many times do the same boundaries need to be tested? Doesn't he know that I'm very serious about nap time? Hasn't he realized that toys will be taken away (just like yesterday) if he continues to throw raging fits? And privileges will disappear if I hear name calling (like you're a freaking stupid head) aimed at me or anyone else. I know every child has to go through it and that it's good for them. Of course every child needs boundaries. Otherwise all they would eat is candy, they would only sleep when sheer exhaustion made them and they would only learn respect from the university of hard knocks. I guess I never expected it to be so hard to take privileges away. I want to give my kids everything to make them happy. But paradoxically sometimes the things that make them most happy are things that leave them in tears. Sometimes the thing that is best for them is a firm "No". Sometimes I have to watch him fall for him to learn. That's hard. I've kind of digressed from Testing Boundaries, but coming full circle, the best thing I can do for my son is to let him know that there are boundaries and they are set for his benefit, not to his detriment. Now if he will only learn that...