an idle brain is the devil's workshop
When one has nothing to do, one is more likely to get into trouble. When I'm off from school, my grandmother is always trying to get me out of the house, while reminding me that an idle brain is the devil's workshop.
idle brain is the devil's workshop
Prov. People who have nothing worthwhile to think about will usually think of something bad to do. We need to figure out something constructive for Tom to do in the afternoons after school. An idle brain is the devil's workshop.