When does poker get hard?

[Black Peter]

It gets hard when you start finding it hard to beat your opponents. LOL. It all depends on YOU. If you think it's hard, then you're gonna get hurt cuz you'll be playing scared.

I've found that it gets challenging at 200NL thru 800NL but then when you get to the really high limit games in Vegas, there seems to be a lot of rich tards to fleece. They don't play the mid-range games.