I don't think so

That was my response to everyone yesterday. Nothing seemed to go right.
Do you want to go on these classroom observations?
No, i don't think so.
Teacher, can I do this?
No, I don't think so.
Can you do this now?
No, I don't think so.
Young man, don't do that, I don't think so.
But, but...
Are you sure you posted everything?
No, I don't think so.
I need to go to the bathroom.
No, I don't think so since you have done nothing. Remember the rule- you cannot go to the bathroom while I lecture.

Maybe tomorrow I'll know so...