What did you learn the hard way?
Take it slow when driving. Don't think just because you passed the driving exam and got your licence that you are actually good at driving. I found myself in unfamiliar territory, screwed up and caused a crash. It was completely avoidable if only I had a little more experience. For those who are wondering, I confused a one way sign with a turn left only sign and as I turned left the other guy in the lane to the left of me creamed me good.