Both my grandmothers had upright pianos and I just knew how to play since I was a child. Nobody taught me. I sounded like a grown-up and then I learned how to read music. I played so well by ear I could fool the teacher to believe I could play the notes. She'd make the mistake of playing the song once and I could play it.
These are people who haven't gone through the legal means to becoming citizens like our forefathers did. They want all the benefits but none of the responsibilities.