Carpe Diem

William Shakespeare writes about opportunity in Julius Caesar. Brutus is urging his comrades to seize a fleeting opportunity in an armed conflict and is given these lines:

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 miseries.
On such a full sea as we are now afloat;
And we must not take the current when it serves,
Or lose our ventures.