Endorphins are released, and you feel good about the gains you've made. It provides a high, and we cling to it. It's why some competitive types will try anything -- even cheating -- to be one up on someone else.
If you ask the average parent or teacher about school safety these days, their reply would most likely indicate how fearful they are. It's easy to conclude school has never been a more dangerous place. I mean, it's true, isn't it?
Habits can hold amazing power in our lives. When we do something consistently enough it becomes subconscious for us to perform that routine. We don't think about it or analyze it, because it has become so ingrained in us to do it that way.
When a college freshman received a C- on her first test, she literally had a meltdown in class. Sobbing, she texted her mother who called back, demanding to talk to the professor immediately (he, of course, declined).