If you are in some kind of organized line you shouldn't be passing anyone until it is your turn at the front. Sometimes everyone will spend an equal time on the front,, then drop back. Sometimes a stronger rider will spend longer at the front than the others. It helps to get to know each other and even talk. I don't like to ride close to people who don't appear to know what they are doing.

edit, They will let me lead to the hills or if it's windy.