Dumb Moments of the Distant Past

Not that I've ceased doing dumb things, but from the 70s:
1) Applying for Ethiopian visas in London (to be picked up in Cairo), then reading a sign in a US embassy stating that severe travel restrictions were on in Ethiopia, so not bothering to pick up those elaborately arranged visas . . . and still never having been to the country decades later.
2) Which led to a New Year's Eve panic in Khartoum, believing the rumor that all airfares were due to increase drastically the following day, and hastily buying tickets to Nairobi. What made this bad was that the death throes of the Idi Amin regime meant all borders south of Kenya were closed, and our air tickets should have been bought for, say, Malawi, so we could work back north from there. Still haven't covered the intervening territory.
3) Believing the nice chap in Bombay that his money changing scheme could net us 25% more rupees when, in fact, it eliminated all our travelers' cheques and foreign currency.
4) Spending a week at Appleby Fair (the largest Gypsy gathering in the UK) and leaving the day before the Trot, because my hay fever was so bad from camping in the fields.
5) Arriving in Morocco, and ingesting a few healthy bowls of kif prior to changing money; then only realizing the following day, and 300 miles south, that I'd left my passport lying on the counter in the bank.
6) Not staying overnight in the Floating Palace of Udaipur, India, because it cost $25 a night and we could live on that for a week.

And more recently:
7) On my final day in Buenos Aires, spending hours looking for effective ways to spend my extra Argentine money, rather than simply wandering through the parklands of Palermo.
8) Not buying the obscure Big Youth LP (featuring an old buddy of mine) from the specialty record store in New York's East Village because it would be awkward to carry around for the rest of the day.
9) Getting on the train in Tunis and deciding that my extra cash was just fine in my wallet, in my back pocket, because all the Tunisians had been so friendly.
10) Not staying longer at the old stone house in southwestern France to sit in a 15 km long traffic jam entering Andorra so that we could relive some old family history.