Me too, kinda. I mean I eventually (through trial and error) noticed it brought up a menu, but god that's not in any way obvious at first. It is funny because until I read something about it I didn't even know what it was supposed to represent.

Apparently its an old icon but I never really saw it (that I can recall) until mobile got popular.

I had a teacher in high school who thought the "graph" icon in Microsoft Word was "library books." She called it the "library books button." I guess 3 lines isn't enough information to convey meaning. Even though the button meant "put this information in graph form" she didn't see that the icon represented a bar graph.