After watching a few videos on here and other sites it seems the pro's all have their specific ranges for calling, 3 betting, 3 bet calling, check raise etc etc.

Is this something that you've sat down and figured out, created scenarios and found examples, and decided what exactly you will do in each situation against specific opponents almost every time? Or when people are talking about ranges is it just ingrained, have they played so much and reviewed so much its just stuck in their head?

To me it seems like a bit of both, and on a few videos the pro has said its important to have your shoving and re-shoving and calling ranges etc figured out in order to do well. So am I sitting down and finding some kind of list out there of these ranges, or am I creating one myself based on how I like to play? And at what stages should I be saying "yeah my 3bet range is the shiz"? I know its always changing and evolving as you progress as a player, I'd just like to know how many tourneys and study sessions in should I have some of these ranges ingrained in my head.

Thanks for the help, and I apologise if I repeated myself

Cheers