Real life and L2 are one and the same. There's always a grind to the top, whether it's hacking away at monsters all day long or doing whatever menial tasks your job may be.
Happiness is finding that spot within each where you can be content each day, without worrying about reaching the top but enjoying the journey. For some that endless treadmill is their greatest joy.
Real life: You get job experience by grinding away in repetitive tasks.
L2: as above
Real life: You have to get useless bits of paper, and other proof of merit in addition to running all over the place in order to go to your next job.
L2: Class change quests.
Real life: You don't make money from grinding, you make money from investment.
L2: as above. Grinding sux, playing the market is better.
Real life: The people who control the world are either born rich or cheated.
L2: Its the same .. the born rich use real money trade, the cheaters use 3rd party programs.
RL: People advertise when you don't want it, be it telemarketing or door to door.
L2: PPL advertise on shout channel ...