I threw a temper tantrum over group meeting, embarrassing myself in front of my students. I went to our group meeting location at the scheduled time, only to find the lights off, no computer set up, and not a single group member present. I called up to the student office saying, "Does anyone remember that we have group meeting today?" They all collectively scurried down to the room, but once they were there, I was so steaming mad that words started uncontrollably pouring out of my mouth.
"I'm really really sick today, and I dragged my ass in to come to this group meeting. None of you could bother to even show up on time. This is a waste of my time. If this were industry, you'd all be fired. No get out - I don't want to see any of you."
I was really really pissed because I was having horrible side effects from the methotrexate that day, and the last thing I wanted to deal with was a bunch of students being disrespectful. Two of the six sent me apologies. But I haven't spoken to any group members since. Oh sigh.