The 32-year-old guitarist said that he still has trouble getting to sleep at night - because his imagination runs away with him, reports BelfastTelegraph.co.uk.
He said that after having kids, he has started sleeping but many a times he felt paralysed by fear and scared to even move and that's been a regular occurrence throughout his life.
"I've always had weird issues with my imagination running wild at night-time," he added.
Fletcher's has been putting his overactive imagination to good use in his stories for children - the latest of which, 'The Creakers,' is all about the things that live under your bed and only come out when you're asleep.
The children's author said that he was fascinated with things that scared him as a kid as he used to watch Michael Jackson's Thriller behind the sofa and the Ghostbusters were his idols.
"My Dad used to tell me stories about aliens and monsters and ghosts, but I never slept because I was terrified. So, I thought maybe it's time to scare the kids again," he stated.
Fletcher released his first children's book 'The Dinosaur that Pooped Christmas,' that sold over 72,000 copies and became the most popular debut children's novel of 2012. (ANI)