"Because it's my life and I believe it's worthwhile to me." I don't understand why people bother to defend personal choices, like education, as if they're in some sort of formal argument. This says more about culture and your own insecurity.
Maybe they value others opinions/encouragement/feedback. A degree of insecurity isn't necessarily a bad thing, it can stop you making mistakes. I wish I'd taken some of the questions of my friends at school Why do you want to get a degree anyway? more seriously years ago.
