New to 6 max - is this a standard fold?

[Bradyams]

Raise preflop, you've got a good hand with showdown value, position, and you'll see him limp here with a ton of crappy hands.

I call the river. He could have been making a move on the turn with a picked up draw, or just trying to push you out, thinking you're just trying to buy the pot with your position advantage. Over time you'll see enough, for the lack of a better word, retarded moves by these players that the river call will be standard.