This happens to me a lot, and I've had a bad week with migraines due to the heat in London. I've been even more vague than usual, and it worries me as I don't want to miss something with work.
A couple of years ago I got really lost just after a focal migraine where I'd had a lot of flashing lights etc. A friend had to come and find me, even though I was somewhere really simple that I'd been many times.
My question really is how common you all find this, and if you feel it has a long term effect, I worry about my memory!