How much time do you spend with your mom?

I am 20 years old and I spend a lot of time with my mom. I have my own apartment so it’s not as if I’m forced to spend time with her because we live together. I get the feeling that a lot of people of all ages eschew spending time with their mothers. This includes people who have good relationships with their mothers. Why is this? Is it something biological? As we get older, do we fly away from the nest and don’t look back? Is it psychological? Do some people just honestly want to avoid their mothers, whether they have good relationships or not?