Speaking to the Second Captains on RTÉ Radio 1 on Saturday, Horgan said: "Sometimes I feel like it’s a good idea to quit while you’re ahead, I mean, we might not be ahead by the end of this season. It might go horribly wrong! The stories came to us really easily and we enjoyed writing it, I suppose we didn’t want to push that. We didn’t want to force stories."
Sharon also revealed she was feeling pretty devastated about saying goodbye to the series: "I've kind of broken down a few times," she said.
"When we did our read-through - because you're reading all six scripts and everyone's there and most people have been involved with it from the very beginning - we got to the last scene of the sixth episode and really, really embarrassingly, I kind of lost my shit a little bit. I just couldn't read it."
Her final scenes with Rob were also very emotional: "Then, on set, when Rob did his last scene, I couldn't even talk to him. I was just like, 'I'm going to email you! Everything I'm feeling now I've got no way I can express it'. I haven't done the email yet."
The Channel 4 comedy began back in 2015 with both Horgan and Delaney winning a BAFTA for their comedy writing while the series has also proved successful stateside on Amazon Prime.
There's no official air date for the final season of 'Catastrophe' with Sharon saying: "We think it's going to go out early next year. But we haven't got a set date yet. We're just editing it at the moment. It'll be ready soon but there's all sorts of stuff you need to work out with the channel [Channel 4] first."