Stuttering less when tired/under sleeping

Stuttering less when tired/under sleeping I don't get it. I noticed this affect at uni when I regularly pulled 36-hour all nighters - at the end of it I would turn into a lucid eloquent mofo (relatively speaking). That was 10 years ago and I've stopped doing stupid crap like that, unless I have to. Like today, I only slept two hours, had a full 12 hour shift, with 2 regional flights, followed by going back to the office. And man, I'm so fluent I don't get it. When I dragged myself out of bed at 3 am my stuttering was INTENSE. Like, really god damn bad. And now hours later, I just had one of the best convos ever. Anyone else experience this?