What is your breaking point for difficulty even if you're having fun?

[LegitHyperbole]

Zippy6 said:

As I've gotten older I'm less bothered by playing on a lower difficulty. I always used to play on hardest but now I'll usually just go for the normal difficulty.

It's really going to change depending on the game how long of being stuck it takes before I stop having fun.

What's the longest you've spent on a boss with this new mindset?