Ok, let me put it like this. The amount of experience you can GAIN before being capped (or Proverbial wall) expands overtime whether you're online or offline. If you are neglecting your path, this means that the amount you can 'gain' stops growing.
The best example I can think of is the "Rest" system from World of Warcraft. The rest system worked like this. If you log out or sit in an inn for LONG periods of time, a special 'bar' starts filling up OVER your exp gauge. When you go our exping that next time, any exp you made was doubled UNTIL you hit the end of that gauge. Now when new people to WoW hear this, they go "Oh, so the best thing to do is to make a character and stuff him in an inn for a year, then I can just level to max level with double the gain!" Wrong. There was a limit at how much you could get, and I think the limit was like 2-3 real life days of sitting in an inn worth of resting-exp.
I've always pictured our exp system like the resting system, only different. The difference is that it's impossible to gain more exp than you would be able to. That's the beauty of the system, in its own way. If you are on "New Dawns of enlightenment" (aka you're very close to a level up), but you are on Proverbial Wall, that should hint you that you can either push endlessly and hope you can reach your level up, or you can be patient and wait one more day or two (depending on how high level you are. After level 10, it does take days to transition from one progression message to the next).