Share 'Do I need to be a physicist to....'

To help my child understand that if you rock climb, gravity is the one rule in existence? I ask this question with a hint of sarcasm, but in a context of not knowing how I will help my boy learn something that I a) never learned myself, or b) know nothing about or don't have a grasp of the subject.  Or am I missing the point that he will pick up what ever he picks up?  I mean, how much facilitati…