I ended up staying home sick from work on Monday, which actually turned into a productive work day, as I spent it reading USB audio device documentation without being interrupted "Mark, can I ask you a quick question?" every hour.
I was not going to go in again on Wednesday, since it felt like someone was stuffing my head with cotton, and not stopping when it was full. But then I checked my work email (silly me), and they really really needed me. So I went in. One of the advantages of living 2 miles from work.
I've been saying "I told you so" at work alot, and this was one such time. Something that I had always been dubious about, broke publicly and embarrassingly while being hometrial'd in the homes of the VP of a Big Potential Customer. We we "thawed" a section of our "frozen" codebase, and I went to work on it. All day. All night. And on into Thursday morning. About the time everyone started in for the new work day, I was wrapping it up.
They were very impressed.
Funny, most of my very best programming has been when I was have been so sick with the flu that I could barely stand. I don't know why. Maybe it's that it makes me decided to slog on through the boring bits, and I'm less likely to get distracted and play with my code.
But anyway, I dragged home at 10 in the morning, pretty much exactly 24 hours after I dragged myself to work, settled in, and the crashed.