There are always "opportunity costs" for anything we choose to do. If I choose A I didn't choose B, so whatever I might gain from B is lost, not realized - the cost of a missed opportunity.
But who's to say if B is a "cost" or a "gain"? That is the actual value of the opportunity? We usually don't know for certain when we make the choice, or until time passes. So rather than make a choice based on FOMO (Fear Of Missing Out), slow down, listen to the message this article conveys and make an informed, rational decision, and stop the paralysis of second guessing yourself.
Nice post intelliguy!