Think about babies and toddlers, who are interested in a toy only until their toddler friend picks up another toy, and then the first kid goes charging after the second in hot pursuit of the new toy. Or the little kid who is being read a book, and three pages into it he wants to get down and play with something else, or even read a different book.
We know that when the kid can read for himself, his attention will probably be kept the entire way through the book. We expect a twelve year old to make it through a half-hour long craft, and if he can't, we wonder if he has a learning disability. We hope every adult can pay attention to life long enough to do the dishes every day, do the laundry every week, and keep the cupboards stocked. If he can't, we say he needs assisted living. (And while responsibility has something to do with it, I'm referring to attention--soapy water left with half the dishes clean because he was bored and wanted to get the mail right then.)
Our attention is so focused on Christ when we get saved, but after a couple or ten years, it gets shoved to the back burner in our lives. I know as a person grows older, more responsibilities are added to potentially crowd out godly things, but as my 6 year old reminded me this morning, passing our tracts is more important than visiting relatives, reading books (and if you know my child, you know that is a big statement coming from him), and even going to church. I don't know about that last one, but at least no one can accuse him of not being focused on winning the lost.
(This last statement is for myself. Everyone else, feel free to stop reading now.) Save the things that don't really matter for when we're on Earth during the millennial reign, and do the things that will last forever now.