I was in tumbling as a young child and involved in wrestling for many years after that. I've had numerous serious falls that have resulted in no injury (other than some bruising). While others that have had similar falls have had fractures.

I can definitely testify to the importance of making falling an instinctual response. When I had my most recent and only fall since being a fully grown man (30 years old, off an unsteady step ladder) I felt my body go completely limp right before my ribs smashed into the step ladder and my subsequent hitting of the ground. While falling I just knew I was going to be hurt, however I ended up only having the wind knocked out of me and a slight bit of bruising at my ribs.

I'd encourage healthy people to take up an activity that teaches them how to fall instinctually based on my own experiences.