Another clueless one but not a Noob! I just go on feel, when the legs scream I move to a easier one and if I am spinning fast I move to a harder feeling one.
When I am climbing a hill I usually know when I hit my granny gear, otherwise no clue. I do normally know what chain ring am in and without thinking move it back to the middle before switching.
And yes there are people who can tell you what gear they were in, I just don't care to process that. :p

