It’s not a story the Jedi would tell you

I'd rather be a sith than a goody two shoes, jedi.
Chopper: I'm just a bloody normal bloke. A normal bloke who likes a bit of torture

It was that part of his programming that could understand Sith writing Benny
It's a cruel code that would occasionally make him bang into things and would enable the ability to feel pain just for a moment and then turn it off again.
Sick folks the Sith

That makes sense now.
Chopper: I'm just a bloody normal bloke. A normal bloke who likes a bit of torture

feedback and validation is an important tool in engineering systems and robotics
no, droids can't exactly feel pain, but he's also a human relations droid, so he's made to mimic human behaviour to make humans more comfortable around him, and so they'll listen to him.
it's the same with vending machines, slot machines and your chatbots. mimicking human behaviour makes them more engaging. if you knew that was a bot insulting and trolling you, i doubt you would care as much to respond, even if you were desperate for human interaction on an outdated message board.

And.
Chopper: I'm just a bloody normal bloke. A normal bloke who likes a bit of torture

Jabba had a robot torture chamber, bro