Re professional mathematicians working on several problems at once. Source needed.

Question

Recently I read a quote from a working mathematician where he pointed out that professionals have to get used to carrying around several unsolved problems at once.

Can anyone help me with the source of this? It was an interesting approach to doing maths.

Answer 1

Could the source be the blog of Terence Tao? Quote:

There will of course be times when one is too frustrated, fatigued, or otherwise not motivated to work on one’s current project. This is perfectly normal, and trying to force oneself to keep at that project can become counterproductive after a while. I find that it helps to have a number of smaller projects (or perhaps some non-mathematical errands) to have at hand when I am unwilling for whatever reason to work on my major projects; conversely, if I get bored with these smaller tasks, I can often convince myself to then tackle one of my bigger ones.