An awkward or unsuccessful first experience, followed by better, highly successful subsequent experiences of the same kind. Like when you make a batch of pancakes: The first one turns out messed-up because you're out of practice or haven't made pancakes before. The second and following pancakes come out perfectly round and golden.
Girl 1: "My new boyfriend is so great, but when we had sex for the first time, it was awkward and terrible. I hope it gets better. I really like him and he likes me."
Girl 2: "Be patient. It's just like the first pancake. I'm sure it will get better."