I've been sleepy all day, so I drank four cups of coffee over the course of the day. As befits my laughable caffeine tolerance, they were decaff; four cups is over twice my average coffee intake in a working day, but it's still four cups of decaff.

All evening I have felt wired, light-headed, and jittery. I'd thought my tolerance had been on the increase recently (it had been taking me two cups of decaff to wake up in the morning rather than one!), but if four can still get me into this sort of state then I think it has a pretty long way to go yet.

Every so often I've wondered if I was just imagining my ludicrously low tolerance, and if it was just psychological. Well, it would have to be some pretty strong psychology to do this to me.

Now I just hope I can get to sleep OK…

I slept mostly OK, as it turned out, although it took me a while to drop off. Avoiding anything caffeinated at all today in the hope that I'll do better tonight…

Meanwhile, I've bought another shiny new flatscreen monitor to go with my other one, so once I install it this evening the only remaining CRT I use will be the TV. Mmm, shiny toys.

One of the many things I like about shopping at World of Computers is that they're a small enough operation to recognise people's faces. I actually paid for my monitor on Saturday, and collected it at lunchtime today, and on the way there I was trying to remember whether I had the right paperwork that proved it was me who'd paid for the thing. I needn't have worried, it turned out, because the sales assistant took one look at me and knew exactly why I was there. (I'd have felt uncomfortable if I'd told them I was there to pick up an expensive prepaid monitor and they'd accepted my claim without proof, since it might imply that someone else could have walked off with my monitor, but since they matched the order to the face without prompting then I'm reassured they really did know it was me.)