There's one fellow who I occasionally see commuting to work, either on a Trek hybrid (narrow tires) or, more recently, on a road bike. He definitely works out, built like a brick poop house and his pedalling style and facial expression looks like he's working out on his bike. Occasionally, we'll be travelling in the same direction (he's always passed me on those occasions) and I will issue a "good morning" or some other pleasant greeting and never get a reply. When we pass in opposite directions, my nod or wave will not get a response. However, I will get greetings, verbal or otherwise, from almost all other cyclists, whether or not I have initiated them: cyclists include members of our local cycling/racing club in their club kit who you would think might ignore mere commuters.

Do you greet others? Do you respond to greetings? Do certain individuals seem to ignore you?