Why Why Why?

I take TIBS bus service no. 180 to my IA company every morning... Thus very often I have to cramp in with the students who would also be going to school at about the same time as me..Yesterday, I came across a incident that really baffled me..This is how it goes. the 180 bus would pass by a busstop whereby there were a few schools nearby as such at that stop there would always (or most of the time) many students alighting at that stop. Yesterday morning as the bus was nearing the stop the bus driver deliberaty slowed down as he was approaching to stop expecting to hear the bell, but the bell never came even when the bus was just about to enter the bus stop, there was no bell..so like all bus drivers, the driver accelerated then right at in front of the bus stop, finally the bell came. the driver have to jammed on his brakes bringing the bus to a screeching stop. then let the students alight, there were at least 15 students alighting but NONE of them actually bother to press the bell before the bus reach the stop. Y is that so? They were too tired? and ALL of them were sleeping? or the bus is too packed thus ALL of them can't see that they have reached their stop? or they think that pressing the bell in advance is a very "paiseh(lose face)" thing? I really don't understand the reasons for them to press the bell so late. It's a very dangerous thing for the bus to suddenly jammed their brakes, wat happens if there'a a tail-gater behind? this could have easily cause a accident...mabbe the students don't understand the seriousness of this matter ..and being at the front of the bus at that time, I do heard the driver grumble abit but being in the service industry I guess they just have to take it... So just do hope that we Singaporeans can spare a thought for these bus drivers in future