I agree with lesson #2 that you posted. Grass is much softer than concrete, and I will put a large amount of money behind that. Falling is part of cycling, and you just have to go down sometimes. One lesson I learned is that you need quick thinking and common sense to become an experienced cycler.
Learning fast is one of the ways that we can get better with cycling. This is one reason that I always feel alright when I make mistakes since it is one of the ways that I can improve.