Agreed with the analogy, Dick, except for one thing: The nature of time means that we can only ever look upstream and make guesses about downstream. So there is an artificial "barrier" around "today" or "as far as we can see from here", at any one time. That barrier, artificial though it is, affects how people think of the stream. For example, for some people "traditional"= "the part of the stream we cannot see from here", and it may hold for them greater allure (or not, depending on tastes). For others, the reverse is true.

Me, I am grateful for whatever comes my way.

(God, but I am in a very metaphysical mood. Do I exist? Pinch me, quick!)