I smoke occasionally with friends, and when I am under stress i will get the "I want a cigarette" thought pop into my head, followed by the "wait a minute, why do I need a cigrette? I don't need a cigarette". But there is no physical feeling that goes along with it (other than stress).

Does it vary from people to people? Is it just a recurring thought or is it something more? What does a craving feel like to you?