Moaners

People do not complain when they think that things are going their way.
They only moan when they encounter an obstacle.
The urge to complain reflects a need to be heard.

The moaner feels cheated, marginalised or let-down. Instead of addressing their own faults, they look outward. 

Another student will quietly endure hardship, set-backs and difficulty.
They might politely ask about their progress and seek tips and pointers.
A moaner looks for somebody else to blame.