WHY DOES A BOAT LEVEL WAKE IN THE MIDST OF WAVES?

It's like when you're in the middle of telling a joke and someone interrupts with a question or a poorly timed aside. When they're done talking it can be hard to pick up where you left off. The moment passed. The timing is off. You've lost your momentum. It's the same with a wave. It's just rolling along when a boat comes along and cuts right through it, and it can't pick up where it left off after the boat has moved on.