DEAR HARRIETTE: I never taught my son how to manage money. Now he is away at college, and it seems like he is always asking me to add money into his bank account. I see that he is not buying anything extravagant — mainly he buys snacks and things for school — but I cannot afford to be his ATM. Plus, he needs to learn how to manage what he's got. I'm sure he is going to be mad when I tell him I am …