Of course, life doesn't really begin at conception, either. Sperm and unfertilized egg cells are just as alive as fertilized egg cells are, after all. Life carries forward from one self-replicating cell to its replicant; it doesn't emerge spontaneously from inert materials.

So does nothing interesting happen at conception? Well, that's not true either.

What is created at conception is not life, but a unique individual, one we consider importantly different from other organisms (well, we sometimes consider the difference important).

Seen from this perspective, something interesting happens at birth, also: independent viability seems like an important part of what we mean when we call something an individual.

And seen from this perspective, something interesting also happens at some less-clearly-defined point after birth... a newborn infant isn't viable in the same way a mature adult is.

Of course, "independent viability" for a human is pretty much always a matter of degree. Our social groups are part of our identities, and much of our viability depends on them.