As an adult, I have some power and can actually deal with stress. I can choose to work extra hours to reduce work stress, or the opposite, and the consequences are largely my own doing. If someone is giving me trouble, I can tell them to go away or remove myself from their influence. If work gets too bad I can always quit, if I hate my neighbors I can move. Not that these things are trivial, but as a child, you don't even have options. Hate your teacher? Hate your parents? Tough. Don't like a class? Tough. I think people often glorify childhood and forget how little control you have over your life then.
Which doesn't mean that I don't want to be an adult who spends time at Toys 'R' Us.