It just means your life is not really integrated with the life of anyone else at the moment, which is fine when you're young: out of your parents' house and independent, but not yet ready (or able, what have you) to get a steady life partner and move in that direction. It's similar to me: there are a lot of people that I care about, but aside from the degree of financial support from my parents that i still rely upon (which isn't all that much in the grand scheme of things. I would just have to switch to taking classes part-time and work full-time, and i'd be able to support myself), there's no-one who, if they died today, would really "change my world" in a fundamental way.

When you're still a child, losing a parent/sibling would be devastating. When you're older, losing your significant other or your child could or will be devastating, but in-between, you're just out for you, and there's nothing really wrong with that.

Similarly i think we all waste some time navel-gazing about what we could have done differently, though that is just that: a waste. The bigger question is "what could i do differently right NOW?" or "what could i do differently in the near future?" If you think you're on a path that'll work out, stick with it, enjoy yourself as much as is practical, and don't spend too much time dwelling on what could have been.

Monster Hunter: pissing me off since 2010.