Question

What is the universally accepted standard of flexibility that you should compare yourself against?

Answer 1

There is no absolute measure of flexibility.

Answer 2

There is not such thing as a universally accepted standard of flexibility because there's no material that is taken as a reference point. You can't say it's twice the flexibilty of rubber or twice the flexibilty of bamboo or anything similar because no official reference points have been established in the SI system.