The lecture was not interesting at all; it was mind-numbing.
- have (something) in mind
- have a lot on one's mind
- mind is buzzing
- have a mind of its own
- mind the store
- have a good mind to (do something)
- enter (someone's) mind
- get a load off one's mind
- turn (something) over in one's mind
- have half a mind to do (something)
- have a closed mind (about something)
- of one mind
- boggle one's mind
- Out of sight, out of mind.