This is the gist I got from this post, and while I agree with the statement I think it is too simplistic.
I am one of those persons that "have a long list of goals, desires, and wants for your life" as teased in the article. I think it's clear that focus helps to achieve an item on that list. It's the issue of deciding what to focus on, when multiple items are competing for the 24 hours we have per day. Most life-advice, as the article, starts off with stating the conflict and immediately jumps to the conclusion. The hard part is in the middle.
Personally, I came to the conclusion that everything I postpone to a later stage in life might just as well never materialise. If I can't live with that thought, then it has to be done concurrently.
That's probably different for short-term project that the article uses as examples, but these typically aren't the items I'm conflicted about.