Breakdown of Non penso mica di essere pazzo!
essere
to be
non
not
pensare
to think
di
to (linking a verb to a following infinitive)
Questions & Answers about Non penso mica di essere pazzo!
Why does this sentence use di essere instead of che io sia?
What role does mica play in this sentence?
Is it completely wrong to say Non penso che io sia pazzo?
Yes, it sounds very unnatural in Italian. The strong rule is to use di + infinitive whenever the subjects match. You only use che + the subjunctive when the subjects are different, for example: Non penso che tu sia pazzo (I don't think YOU are crazy).
If a woman were saying this, would any words change?
Yes! Even though the verb is an infinitive (essere), the adjective describing the speaker still has to agree with their gender. A woman would change the ending and say Non penso mica di essere pazza!