the event sheet automatically loops - every tick (60 times per second), so normally you don't need to set up another loop, unless you want something else to happen multiple times per tick. So, generally, things will always keep happening until a condition in the event becomes false... (without using Repeat or While)
It took my son a while to wrap his head around that when he was learning C2. The other thing he kept doing incorrectly was using Wait (thinking it would pause the event sheet). I see a lot of other people get confused with that too.