ways of the tide

All my life I have been a peacemaker. I am a bridge between two lands and the river is roaring beneath my floorboards. My self-given job as a bridge is to be a safe passage over to the other side. Usually, the furthest people are willing to go is halfway. But that's okay. They meet in the middle.
There are many who hesitate to cross over, afraid to step out over unknown territory. Fear, pride, anger and indifference seem to reign in the minds of these people. I am saddened by the unwillingness to see new, wonderful things on the other side, and my floorboards long to be trodden upon. They soon start to wither with old age and gloom. I am forced to realize: I have no purpose here.
Instead, I recraft myself into a boat. Finally, I am free! I no longer have to stand with one side in each land, no longer do I need to wait in vain for people to meet in the middle for understanding. As a boat, I sail the big sea from harbor to harbor, and freedom is the wind in my sail. Every now and then I pick up a lone hitchhiker wanting to pass over to the other side. My flag waves happily in the wind as a goodbye as I sail on.
In the place where I used to lie over the river, there is a pole stuck in the ground with a sign and it says;
If you want a bridge
you need to build it yourself