It was the first time I'd attended a Catholic service in about fifteen years. The procedural memory -- stand, kneel, sign, sing -- was all intact. I knew at any given moment what I should have been doing. I actually had to make a conscious effort not to participate; if I just zoned out, the automatic part of my brain would have taken over and I'd have been standing and kneeling with the rest of the family.

But really. Priests and parishioners have to assume that not everyone attending a funeral is necessarily Catholic. I don't think many would give you shit for not participating. I certainly suffered no blowback (from the clergy).

and it wasn't a full mass, just a service. Guess they weren't church goers, just baptized in the faith so you get to end with the faith, or something like that I guess.