An insightful question, and I like the way you phrased it.
I notice that it assumes three things: first, that there is, in fact, a “meaning of life;” second, that if there is such a thing, only one and not more exist (why can’t there be two, or seven, or even infinite meanings?); and third, that such a meaning is constant, rather than variable and relative to any given person.
It’s important to remember that “meaning” is a human idea, imposed on the universe by us, and not vice versa. One way to see it is as follows...
There are two kinds of meaning (or purpose): internal and external. The first is what people hope to achieve in their lives through certain actions (e.g. the purpose of a visit to France could be to learn about French culture.) The second is the notion of a purpose beyond our daily lives, an ultimate aim that would justify our existence. While the first is a useful concept, grounded in reality, the second is based on our desire to feel necessary and important. It doesn’t sit well with us that there may not be a reason for our existence. So distasteful is this possibility, so offensive to our sense of worth, that many prefer to invent a purpose rather than consider its likelihood dispassionately. Unfortunately, uncomfortable conclusions can’t simply be wished away.