In line with what Tater said . . . 80% of my robot making skills I learned outside of class.
However, in school I was surrounded by very intelligent individuals that really influenced my own intellectual growth. School teaches you things that you didn't know you didn't know. It also forces you to learn things that aren't fun to learn, but can be very useful.
I didn't regret going to CMU for a second . . . but still debating on going back for grad school . . . I can teach myself whatever I want, but its the environment that can potentially accelerate that process
Plus, employers who know nothing about robotics can only judge you by your degree