Roman Catholics attend mass every Sunday. Some of us are present mentally and physically. Although we are physically present, there are still mentally absent ones. One cannot prove this unless you cross-check with the person. We lie to others, but we should not lie to ourselves.
Oxford dictionary states - Obsession is the state (of mind) in which you can only think about one person or thing so that you cannot think of anything else. The meaning does not mention if the obsession is good or bad.
When someone calls you mature, two things strike your mind: physical and mental maturity. The physical look is quite obvious and conspicuous. However, it isn't about age, no matter how physically mature the person is. Looks are not a guarantee of a person's mental maturity.