Yes. Idle mind is devils workshop. Something boredom may lead us to do something wrong. It will get us in trouble. we can avoid the same by cultivating some habits like book reading, games etc.
Boredom fills our minds with unnecessary thoughts and we do tend to do certain things which we normally don't do and therefore we must keep ourselves busy so that our mind remains engaged....
ya i believe because free mind think about the wrong matters as well as good matters and find about the solutions but if not succeed it gets disappointed then.