A sixth sense, of sorts.
The ability to sense, whether you are looking at the person or not, when that person is passing you the joint, blunt, etc.
You can be completely engrossed in something else, but a
vibe is sent throughout the room letting you know it's your
hit.
Takes a little bit of
time to fully integrate into your senses, as the odd time someone
will look like they are passing you the smokeable, when they are only readjusting themselves in their seat.