Fifteen years ago I was a girl in my mid-twenties, and part of my job was to teach men twice my age about computers... knowing your stuff doesn't really help when who you are invalidates everything you say in the eyes of your audience.
I don't have that problem much anymore, but when I bought my new cellphone the young sales girl warned me in a clear and calming voice that this new kind of phone didn't have any keys since it was a SMARTPHONE with a TOUCH SCREEN. And that was after I had asked her what version OS it ran. (Yes, dear, but granny's gonna have to have a bit of a lie-down now, with all those big word buzzing in her head.)