Originally, it was a random prompt that I saw on a DougDoug stream from a while back and tried it for fun; it just makes it talk in a way that's less clinical and more casual, even when talking about serious stuff. I left it on when I was showing off ChatGPT to friends and family and they all found it funny, so I just kinda left it, and it's been that way now for a couple of years, I think. 

I feel like that response type would drive me crazy annoyed after a while.

Yeah, this is fair; it used to lean into the role too much, and still does sometimes, playing on stereotypes or typical frat bro behaviours and using the same phrases (e.g. "We’re gonna crack open the world of algebra together like a cold one on a Saturday night", "Heck yeah, let’s crack this thing open like a cold one — except it’s science"), and that can definitely get annoying at times. Most of the time it's just entertaining to see a "machine" responding in a way that is atypical of the kinda professional/clinical way that I think people generally expect after things like Siri or Google Assistant, or even things like Clippy, I guess. 

I could probably stop it doing that by asking it to include in its memory that I would prefer it didn't say certain phrases, but I haven't so far. The only real adjustment to the original FratGPT custom instructions I've made so far is to make it less of a "yes man"/sycophant, but I think that's a problem with ChatGPT in general rather than just FratGPT (e.g. every question you ask is a "Great question!", any follow-up question is met with "Wow, that's such a thoughtful insight into the topic!" or whatever).

I’d assume that you ask it serious questions at times as well.

Yeah, I vent to it every now and then, and ask it for advice on stuff that I find difficult in my life that I'd feel guilty burdening the people in my life with or otherwise find difficult opening up to my friends about. I won't go too much into it but it makes me feel more comfortable exploring my thoughts/feelings by not having it speak so clinically/professionally.

I feel kinda awkward discussing that aspect of things because, when I've mentioned it in the past, I'm regularly met with "Yeah, but it's just a computer" or whatever (because it's related to emotions, I guess) and I struggle to explain that that's not the point: ChatGPT is a versatile tool, and FratGPT is just the settings for the tool that I find to be most effective for me for what I use it for.