Optimist-Pessimist-Dunno

Optimist : Half full.
Pessimist : Half empty.
Dunno : What?

Optimist : This problem is challenging but I think it can be solved.
Pessimist : This problem is very difficult. I don't think it can be solved.
Dunno : Problem? What problem?

If you have optimists around you, that's good. You will find it easy to cooperate, collaborate and synergise. As long as your plan is specific, realistic, achievable and consistent, you can have good teamwork and things can go on more smoothly.

If you have pessimists around you, things can still be done except that it takes a longer time and it is more energy-sapping. You may have a more challenging task of communicating, training, motivating, persuading and convincing them to get going.

If you have 'dunnos' around you, ........ (Please help me to complete this sentence.)