We have a tendency to do what everyone else is doing.
And to wait for someone else to make the first move.
In high school, I would often arrive to my next class and find several of my classmates waiting outside the door. The teacher hadn't arrived yet. The lights were off, and the door was presumably locked.
After all, why would so many people wait around the outside of an unlocked classroom?
Nine times out of ten, I would try the doorknob, and it would be open. With a laugh of slight embarrassment, my classmates would go in and take a seat.
Don't wait for everyone else. Sometimes everyone else needs you to make the first move.