I am currently working on a No Fap guide where I go into each reason why people fap and how to fix them. So I am asking you if you know to put it down, or if you dont know yet to journal about it and put it in the comments so I can help your specific case. Take Care!
I think boredom is a big one. When you are bored and don't have much going on your brain will usually just default to the most stimulating thing which could be fapping.