well i can only speak for myself in saying that many "tricks" will come as a matter of survival like hopping a curb to avoid being hit or skidding when being cut off, after that a "purist" imo would be the only one wrenching on their bike, and you've gotta test the strength and peramaters of your work, is my chain/line right, are my brakes right, is my bike balanced, and boredum leads to more tricks, or maybe you just have to feel cool...

... i feel cool when i stay with traffic or fly by it and do it with a certain amount of security