Maybe,
It depends on what your opinion on the best things in life are. If you're materialistic, like many of the teenagers, adults, and children living in today's society in a few countries are, then this quote will never mean anything to you. Now, this quote has absolutely nothing to do with materialistic things, and if you think that, you really need to do some research about it before saying something like that.
We all share many things that are free in a sense of using them. Sure they are all somehow linked to having spent some money on it, but regardless.
From my research, this quote came from a song written by B.G. DeSylva, Lew Brown, and Ray Henderson for a musical. And I strongly believe that these lyrics do mean everything.
The moon belongs to everyone
The best things in life are free,
The stars belong to everyone
They gleam there for you and me.
The flowers in Spring,
The robins that sing,
The sunbeams that shine
They're yours,
They're mine!
And love can come to everyone,
The best things in life are free.
But honestly, things aren't always so direct. Learn the metaphoric terms of these quotes and you'll see that they are precise.