A good example of pushing yourself to get to the next level is a recent snowboarding trip I took. There were four of us with 2 being completely new to snowboarding. The first 2-3days both guys stuck to the green slopes and progressed quite well. On the afternoon of the 3rd day one of the new guys comes with us to some blue runs and gets beat up pretty good, though he stuck with it all afternoon and by the end of the day he could make it down this blue slope without any falls or stopping The other guy would not for the life of him leave the green slopes. On days 4-7, the first guy who came with us to the blue slopes, is now able to go down most all blue slopes and even went down a black diamond. The other guy never left the green slopes for the entire trip.
At the end of our trip, it was extremely apparent the skill difference between the two new guys, and this was only after 7 days. Unless you push yourself to new levels, you will never experience the new things that happen at those levels, if you don't experience them you never learn how to master them. Thus you will be stuck on that 'green slope' forever.
my 2c's.