Everybody who is anybody has kids. I find it almost impossibly difficult to find anyone over the age of 30 who hasn't already thrown a kid into this world, or who isn't planning to do the deed. Maybe babies are like little meaning parcels, delivering meaning and purpose to adults along with a lot of poop and vomit. And, as Shadow has said before (can't find the link), parents can then pass on the meaning-baton, the burden of meaning, to their little bundles of love. Aww, ain't life great?
BUT, in my view, tossing children into hot lava, i.e. this world, is only the most meaningful thing in this world not because it holds any meaning - IT MOST DEFINITELY DOES NOT - but because it releases a lot of love and pleasure chemicals into the brain. And I suspect that's exactly what people mean when they talk about meaning and purpose - happiness. Everlasting happiness as opposed to an actual purpose. Great happiness or fulfillment basically equals meaning, even if there is no purpose involved at all. I have said this many times before, but if the purpose of life were to kill puppies, then day in, day out, we should all be perfectly happy killing puppies to serve our Lord and Saviour, Khat F. Eline (if the intuition about meaning were correct). This is why Christians are not perfectly happy - meaning doesn't automatically (auto-magically) create happiness, and create it forever. It gives you something to do, but unlike what people associate with the term 'Meaning of Life', you'll probably get bored and unfulfilled within a certain amount of time.
But is that it then? Does it only take one child, and then people have had their fill of meaning, understand the meaning of life, and can check out in peace? Most certainly not. Why else would people have more than one child then? To keep feeling those new baby pleasure chemicals. To keep messing about with the amount of suffering in the universe. But I digress. Some people may indeed find that children give them endless meaning, but a lot of people, when the 'endless' joy simmers down to a stable love, simply find that they feel the whole thing has been a waste of time. That the pressures and pains and boredoms (serves them right says the resentful fellow in me) of raising kids eventually culminate in feelings entirely antithetical to the initial 'I have discovered the meaning of life' surge of emotions. How many people truly believe having children was the best thing they ever did? How many people don't? It would be impossible to tell unless we could read minds. But it makes you think that perhaps this childrearing business isn't so tantalising after all. Look left, look right, don't have kids, don't run across the road.