I’ve found that in some cases it’s the opposite. Sometimes, if somebody makes a joke like “I suck, hahaha”, you need to take it more extreme, like “who told you??? hahaha”. Depending on a bunch of factors, sometimes if you respond to an “I suck, hahaha” with “no you don’t, you shouldn’t think that”, they’re gonna start wondering why you couldn’t tell they were joking and start worrying that maybe they actually do suck.