I believe he's saying that we start out our lives innocent and having fun but through learning we realize that life can go in many directions, like the leaves and dreams. We as humans are free as the wind as hopefully we learn along the way, although what we come to understand is that some things in life are changeable but some things like the sea on the tide are not. More than this we as humans know nothing about what's beyond our life but through faith Ferry may be saying there is the hope ("More than this tell me one thing"). What though is the one thing he wants to be told?