My first playthrough of Dark Souls was as a Thief. Boy did that ever teach me the love of dashes, rolls and especially the use of both into setup for backstab. I remember just standing in the first zone fighting the first few enemies till death over and over with no expectation of progress. I was just teaching myself how to fight, experimenting with what was possible. Like how I go into a new fighting games 100% expecting to lose my first fifty matches or so. The objective isn't to live. The objective is to get good. Frame counting, understanding of invincibility frames, I went completely nuts with it. When I was done, I was untouchable by humanoid enemies. Parry, Dodge, Parry, Roll, Backstab, Parry. All enemies are dead. Move on.
My friend who plays only pure two-hand strength builds could not believe my accuracy and speed with these mechanics.
You refine those skills in a relatively low stress environment, they'll save your bacon later when you're fighting something that's fucking terrifying. If I'd streamed that playthrough it would've been super boring though.
That was really fun riiiiiiiiight up to meeting the first enemies in the game that had no backstab opportunity. Then I got rekt. New training ensued. Repeat until Kiln of the First Flame.
I'll probably do the same thing in Bloodbourne.