The most important difference between Level 1 and Level 2 actions is that Level 1 actions tend to be additive, while Level 2 actions tend to be multiplicative. If you do ten hours of work at McDonald's, you'll get paid ten times as much as if you did one hour; the benefits of the hours add together. However, if you take ten typing classes, each one of which improves your ability by 20%, you'll be 1.2^10 = 6.2 times better at the end than at the beginning: the benefits of the classes multiply (assuming independence).

Nitpick: You cheated by stipulating that each typing class has a multiplicative effect. This is just saying that additive things tend to be additive, while multiplicative things tend to be multiplicative.

I agree with your larger point... but the multiplicative effect comes in because the typing gains apply to every typing task you perform over the rest of your life.