Imagine a man walking down a corridor. At intervals along the floor of the corridor are keys. The man stops to pick some up keys and leaves others. Maybe he cannot hold all of the keys. Perhaps he is lazy and does not choose to pick up a particular key. He comes to a large room with many doors. Each door can be unlocked with a key. A few doors are already open. The man looks at the doors and reads the signs on them. Some of the doors are very attractive. Some hold no interest for him.
Unfortunately, a few of the very attractive doors require keys that he did not pick up, and he cannot open the doors. The keys are opportunities. The corridor is your life. The room is a cusp (where you have to make a choice) in your life. The doors are goals or rewards. If you do not grab the opportunities as you travel through life, you will not be able to unlock the door to your goal or reward.
Get good grades NOW!! so that doors remain open for you for scholarships, or even college. Advance NOW!! So that you can finish your Eagle requirements before life throws roadblocks in your path. Exercise NOW!! So that you will have a better opportunity to make the team next season. Pick up the keys NOW!! So that you can open the doors when you want to or have to make a choice.
If you can talk like Rod Serling, you can have some fun with this.