In my own personal case for the first type of situation, it's because I don't drive due to a crippling fear that, due to my lack of experience, I'm going to end up killing someone or someone's pet. (Ironically, in order to get that experience, I need to keep driving)
I'm slowly overcoming this fear, but that's the case.
And no, I don't fancy the idea of being shepherded around my entire life, either.