I started my first job with no degree and no real experience. It was a sink or swim kind of place. Six months in, I was working on a bunch of projects independently, then they hired a new junior developer, and told me it was my job to mentor him.

a lot of the time I knew what to do to get the job done, but I didn't know why. He always asked why... Learning something is one thing, teaching it is another. This guy was the best co-worker I've ever had because he pushed me to be much better while we learned together.