Lounge etiquette and it's non existence from airlines most frequent flyers....

[Blackadder]

I couldn't agree more! Especially as in many cases the announcements are either way to early for close gates or too late for far gates meaning a very fast walk, jog or run otherwise you risk having no overhead locker space!

As a rule I get to the gate 20 mins before boarding for AA flights, the tendency for overhead space to go quickly is a very big motivator to ensure you are at the front of the queue.