tantrum = bad kid?

Before I got married or pregnant, whenever I saw a kid at the mall throwing tantrum, I always thought to myself "what a naughty kid" or "poor mom".
Yes, it appeared to me that the mother had a very stong willed kid that would get really mad if he didn't get what he wanted.
Now that I'm a mom and has a kid who had tantrum, and also because I read about it, I know that tantrum happens. Not because my son is bad. Even an angel baby could have tantrums. They happen when your child is tired, hungry or not feeling well. So make sure he has enough rest and well fed.