Dabbler:  taking a sculpture class at the local art center.  Great diversion.  No intent to develop skill.  Just wanted to try something new.

Hacker:  computer maintenance.  Learn just enough to fix things.

Obsessive:  Language.  Tried to take French in college and could not keep it up.  Took more time than all my other courses combined.  Dropped the class.

Mastery:  Swimming.  Swam competitively for 12 years.  2-4 hours a day.  10,000 hours of practice.