genetics vs training

okay so today i was sparring with one of my friends and we ended up going shin to shin - mind you i do not wear protective gear when i train - and my friend is a kicking expert who has spent a great deal of time conditioning his shins, and yet today we had to call a timeout because i deadened his leg - also mind you i have boney legs, and do not spend much time on shin conditioning, yet my shin doesnt even hurt while my friends shin is bruised.... so what is the point of all his conditioning against someone like me who just has naturally strong legs? i thought this might make for a good discussion, since it seems that some people are just naturally more built and have a higher pain tolerance than others.... also, do you have any advice for my friend on how he can strengthen his shins without hurting himself or damaging his nerves? thank you