This is the second time (and please the last time!) that I have learned this: Find out if the line for the bus home is yours or the next one!
This was the second time (ditto) that I assumed that the line forming and waiting was for my bus, only to find out, way too late, that my bus was loading on the platform all that time, and then it left! This time it meant waiting 45 minutes more because I missed a bus for which I was plenty early.
So ASK (there is that ask again!) the people in line which bus they are queuing for!
Jane's Lessons Learned 
Looks like you had to make a new plan, Stan.