Economists are taught to assign value to everything. Even things that other people wouldn't generally assign a cost to. One way they do this is by using the concept of opportunity cost. For those of you that might not know, here it is in a nutshell. Opportunity cost is the value of the things you give up by making a choice. If you have one dollar to spend at the dollar menu, you can get a burger or some fries. You cannot get both. I'm going to apply this to something a bit more abstract. If you want to go out too dinner with your family and someone suggests a great Thai restaurant and someone else suggests Italian. You can't eat at both. If you eat at one you'll be full. If you compromise and only eat a bit at one restaurant then get a small plate at the other, you won't have gotten the full experience. There is always a cost.
But opportunity is a difficult coin to spend on purpose. You must always see what you want and what you cannot do because of it.
If I choose to write, I cannot successfully pursue a hobby at the same time. I cannot spend that time with my wife. I cannot strengthen my relationship with my children, friends, or siblings. Writing a book takes a lot of time. That's your time. Time that you could be doing other things. Time that you probably want to be doing other things. Time that your friends, family, or others might want you to be doing other things.
Is it worth it?
You can spend this coin on purpose. You can use your opportunities to bring you to many different goals. But if you don't make your choices on purpose, you may never get your book. Do you want a book? Do you want to be successful in your writing? The next time you have a choice of what to do with your time, consider what it's costing you. If you have good friends, then they'll understand. You've got to buy your book, and opportunity is the only coin that will buy it.
Spend your opportunities with intent.