I first came across these little beasts nearly 40 years ago camping in the Pyrenees. People really do confuse them with humming birds, and they're pretty big (for moths) so it's an easy mistake to make. They'd hover around while we drank our Plymouth G&Ts... Those were the days...
‘Grey lump with orange wings’: hummingbird hawk-moths descend on UK gardensBoom in hummingbird hawk-moth sightings put down to hot weather, strong winds and food scarcity in Europewww.theguardian.com