Following a fellow commuter has many advantages! I sometimes get caught in a commuter race and edge pass a fellow commuter only to be overtaken later but an experienced move on the other commuter's part.
What good move? Like using the pavements in heavy traffic (sure you can zig zag through the traffic, but it's really dangerous. Espeacialy with Singaporean drivers not used to cyclists on the roads), or taking an alternate "short-cut", or a line without pot holes! All true stories! hahaha.
It's times when I'm tired and just lag behind other commuters that i realize that most of these commuters are much more experienced than me, and they know a thing or two about the route. So the next time you see a commuter ahead of you, try following them!
But dun be stalkerish! Duh! Following others is easier, irresistible even. Provided you are following instinct, aka the opposite sex.