Fr Jim Cogley
There are a few lines from Shakespeare in Julius Caesar where Brutus is speaking to Cassius about how they must move forward in their military campaign and seize the opportunity of the moment where he says:
There is a tide in the affairs of men, which, taken at the flood, leads on to fortune. Omitted, all the voyage of their life is bound in shallows and in miseries. On such a full sea are we now afloat, and we must take the current when it serves, or lose our ventures.
There's a tide in the affairs of men that is like a power or force that ebbs and flows in time, and one must go with the flow and make the most of each opportunity as it presents itself. Waiting around only allows your wave to pass its crest and begin to ebb. If the opportunity is missed we find ourselves stranded in miserable shallows.