Is it fair to punish someone for a wrongdoing if they committed it while not being aware of what they're doing?

Depends on the situation.

If they already knew about something related to that topic. Therefore they would already know of the situation and the circumstances.

It depends if your blacked out drunk or high as hell than yes, but if your senile or have Alzheimer's than if say no. If u have PTSD I really couldn't say, probably yeah