catchup is good because describe something that helps you reach the same standard usually after you have missed something such as lesson or opportunities to practice.it is the activity of trying to do as well as a competitor or of trying to reach a level of achievement.
The key point is missed. If you have a good reason for that, it's understandable, but most people don't, they just get bored, get uninterested, get tired, get lazy, find something prettier, etc. You get the picture.