Cigarettes taught me this in college. Definitely the only positive impact smoking had on my life. I would be deep into solving a hard problem, and my nicotine brain would force me to go outside and smoke. I would very often come back inside and immediately get past a big hurdle I was struggling with.

It happened so much that when I quit smoking I made sure to continue the routine of getting up to go outside for a few minutes every two hours or so.