OlliOlli World

Masteries are, effectively, game-long tracking challenges. After completing the first world (Sunshine Valley) and meeting Technicolas, you'll unlock your first five Masteries, which are viewable from the main menu. They are:

(1) Perform 2,000 pushes.
(2) Perform 5,000 tricks.
(3) Perform 2,000 grinds.
(4) Ride 300 quarter pipes.
(5) Complete all 45 of Mike's Challenges in Sunshine Valley.

Completing any of these Masteries (or a Mastery for another character you meet later) will earn you this achievement. I got it for performing 2,000 pushes, but your play style may lead you to earn it by completing another metric instead.