Trumpet - I played this back in elementary school and was pretty good at it. Only played it once or twice in the last decade and a half though, so I’m not good anymore.
Piano - because I know how to read music, I can go up to a piano and (eventually) figure out how to (poorly) play familiar melodies. Never had any lessons though so I don’t think you could really say I can play it.
Guitar/Mandolin - I know these are two different instruments, but to me they are the same, as in on a few occasions I’ve picked them up and strummed for a bit and tried to figure out notes and then gave up.
Guitar Hero - I was really good at Easy and Medium difficulty back when I used to play. Never could manage that fifth button though.
Rock Band - obviously guitar skills from the previous transfer over. I like to think that I am a great singer (though I’ve only ever sang to myself in the shower and in the car) so I was great at vocals. I really liked the drums and was pretty good on Easy but anything beyond that was too much.
Mayonnaise - is gross (except for a very tasteful little bit on a sandwich).