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.
I came here to say the exact same thing. I used to find that the act of prying myself away from the computer to go have a cigarette was incredibly beneficial to my problem solving ability. There is definitely something to performing a simple, repetitive physical task while leaving the mind free to wander.
Like the above poster, I've since quit smoking thank goodness. I don't miss the smoking itself as much as I miss having a reason to get up and treat myself to some quiet time to indulge myself in thought.
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.