Do you know what rope drop means? Not everyone does. It is one of many Disney slang. It means being at the park entrance at park opening (rope drop).
It is VERY, VERY, VERY important. This is a must do to maximize your time in the park. Also, sometimes they will open the parks EARLIER then the posted open time. If you are there 30 minutes in advance you COULD get in early (no promises).
When planning a full day in park make sure to be there for rope drop, it starts your day off right!