I first used the button on my Janome when I had a joint replaced in my toe...funny the things that will get us to try out something new to us. No sewing was harmed by that surgery!
I sewed on my mom's Kenmore as a teen and it had the knee pedal rather than foot pedal. Years (lots of years) later a knee lift on my Bernina confused my brain a bit, I'd press the knee thing and the foot would go up while my brain waited for the machine to go I guess! I was laughing and laughing until my body got more used to what to expect.