I am pretty sure this is the first time I have ever quoted Shakespeare, but I suppose this is a good first. This quote was apparently used by John and Abigail Adams in their letters to one another at the beginning of the Revolutionary War.

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 the shallows and in miseries…

And we must take the current when it serves,
Or lose our ventures.