You're an eligible prince, and your dad (the king) has arranged for you to marry one of 100 available princesses. You want a good one, of course. The princesses are summoned and lined up. You're allowed to meet with each one in turn (not knowing what the rest look like/act like/etc.), and are allowed to either accept or reject. Once you reject a princess, you can't go back to her. Once you accept a princess, your decision is final. What strategy should you use to optimize your final choice?
It's a well-known problem (with considerable variation on theme).
You're single and want a relationship. Your code of ethics prevents you from getting back with an ex. Assuming the pool of potential partners is larger than you'd be able to meet in your lifetime, what strategy should you adopt to find the love of your life?