Antistar wrote on 05/10/18 at 22:32:19:Well that's a matter of perception
and depends on your body size/shape too. This said, American people are taught large drinks are 1L, so when they come to Europe they face a big surprise. That reminds me Drew coming to a French KFC after CDM in 2011, getting his order with a 0.5L drink and protesting like "
J'ai demandé pour un grand boisson"
^ Fixed.
I don't think body size has as much to do with it, as I'm not exactly André the Giant (I'm actually fairly small for a man, and people who see me are surprised that I weigh as much as I do-- I certainly don't
look like someone who's a shade over 100 kg, nor do I
feel like I weigh that much), but what we are surrounded by and therefore conditioned to consider normal. If you grew up in Yuma, Arizona where my cousin lives, you'd think 45°C was a normal summer day.
...Of course, if I was in France and they gave me a too-small drink, I'd just ask them for
un deuxičme 
(or maybe even
un troisičme)
They'd charge me a few extra Euros, but what the heck. If I can afford to come to France, surely I can afford to buy an extra Coke or two. Ultimately it's just a First World problem, because we
could be somewhere in Africa, walking down to the crocodile-infested river, wooden bucket in hand, if we wanted something extra to wash our food down with.