Generous to a fault
Many years ago I was on a three-day off-road ride in France; road-book navigation, run by Chris Evans of TBM mag fame, great fun etc. My steed that year was a 34L Yamaha Tenere - the first model, with massive 34litre fuel tank. Naturally I only put about 10l of fuel in at a time...
First stop on day two, one of my friends pulled in with me and filled the tiny tank of his XR600. Having done so, he offered to put some petrol in my bike to save time. I wasn't really paying attention and realised too late that he had brimmed the tank. About the only good thing about this was that I refused to pay for the excess and had a couple of weeks' worth of riding out of it. The bad thing? I lost count of how often I dropped what became known for the rest of the weekend as 'The Fuel Bowser'.