I think focusing your mind is like focusing a magnifying glass, you can go broad, or narrow, but not both. How far do you go down a path till you switch and try

I think focusing your mind is like focusing a magnifying glass, you can go broad, or narrow, but not both. How far do you go down a path till you switch and try another? I think stimulants increase how far you'll remain engaged on one idea. Related: https://en.wikipedia.org/wiki/Pathfinding https://en.wikipedia.org/wiki/Pathfinding