I got a good wake-up call (so to speak) about diving when tired, when I was in Florida last year. I was working with an instructor to try to polish my cave skills, and on the second day (which was my fourth straight day of cave diving, staying up too late, and coping with some jet lag) she looked at me and said, "You're tired." I asked, "Why do you say that?" And she answered, "Your technique is falling apart. You're making mistakes you weren't making yesterday. You're not following the tips I'm giving you." And I thought about it, and she was right. I did not dive for the rest of that day.
I work night shift, and I often have opportunities to dive the afternoon or evening after I have worked. But even though I can take a nap and refresh myself somewhat, I don't do those dives, because I'm quite certain my judgment is poor and my ability to think quickly and solve problems is going to be significantly reduced.