Sometimes we don't know what we are doing which has turned to an habit until some caring people point it out to us and we are still the one to make choices of changing or not. Overthinking could cause lots of things to one's life and if care isn't taken and we aren't quick to change, it becomes something we won't be able to cope with again. Having positive thinking to overcome that habit is one sure best way to become better at doing things.
You’re very right. The earlier we work on ourselves, the better.