Buddhism.

Mother:  I watched a documentary on Buddha

Me:  On the Buddha?

Mother:  Yes.  He was an interesting chap.

Me:  I know, I've read books.

Mother:  You didn't ever say...?

Me:  No.

Mother:  Why didn't you say?

Me:  I don't know

Mother:  Are you a Buddhist?

Me:  No.  Why?

Mother:  That's the sort of thing you'd do.

Me:  You don't 'do' Buddhism...

Mother:  No, but....well, you meditate and that, don't you?

Me:  Yes.

Mother:  Exactly.