“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.”
Explanation:
Large ships still tend to try to leave port at high tide. Tide comes in, and tide goes out. If you try to leave port before high tide, you're going against the flow, and working twice as hard to make progress. Once it reaches high tide, the flow is going out, assuring success with minimal effort.
Caesar was noting that there are such trends and times in other endeavors as well, most particularly he was referring to politics, but his experience had shown him that it was true in military operations also.
The key to success, he is saying, is knowing that there is such a tide in all things, being able to recognize when they reach their peak, and seizing the opportunity that it affords.
