The best invention ever is... Any period since the beginning of time. The wheel, the internet, space travel, sanitation. or something else? As martial artists and civilised human beings deodorant has to be right up there.
So one of you is working in the garden, while the other is a couch potato. Any you are both smelly without deodorant.
Raita and poppadoms. Seriously. If Indian civilisation had achieved nothing else ever, it could stretch back in an easy chair with its hands clasped behind its head, and with a quiet sigh of satisfaction acknowledge a job well done and thousands of years of progress vindicated.
And a Canadian My vote goes to language though. Language is the technology which allows us to share information and ideas with great precision from simple speech to mathematics. It's allowed all other technologies to be shared and improved to a degree impossible before the formation of language, not to mention the one or two other uses it has...
Air conditioning, without that I would not be posting, there would be no internet....server rooms everywhere would be failing due to over heating. Oh and shoes.... nuff said there
The scientific method. Or the mushroom shaped "skum" candy they used to sell at Ikea (but don't anymore!!). Either of those two.