There is much to write about St. Paul's famous instruction to "pray always," one of the most explained-away elements in all of Revelation. But here, I just want to point out one small thing about prayer, in the too-mystical-to-be-a-useful-definition sense of "looking toward God in your heart."
Imagine if you can someone who prays sometimes. Someone, that is, who at times looks toward God in his heart, but at other times looks toward things that aren't God in his heart. However devout his thoughts while in prayer, for this person God belongs to a set of things he looks toward in his heart.
That's bad enough, but consider the process this person goes through. At one time, he is -- well, "looking toward in his heart" is just the definition of "praying," so -- he is praying to his golf game. Then his hummingbird mind flits elsewhere, and he begins praying to his landscaping. Landscaping reminds him of the beauty of nature, and he begins to pray to God in thanksgiving. After a few moments, he might find himself praying to the parish council, which had better hire a halfway decent music director this time.
"After a few moments, he might find himself...." But he won't find himself when his heart is looking toward the parish council. The Prodigal Son "came to himself" when he realized his father would show him mercy. Similarly, we only come to, or find, or arrive at, ourselves when we direct our hearts to God -- and, similarly, we find our Father shows us mercy, every time we return.
I think the oddest part of this whole process isn't what happens to us the hypothetical person who goes through it, but what happens to God. Which, in a word, is nothing. He's still there, still All-Holy, All-Mighty, still Goodness and Truth and Beauty, still loving us with an eternal and perfect love expressed in the life, death, and resurrection of His Co-Eternal Son.
But, somehow, the human heart is capable of only noticing God occasionally. And, apart from all considerations of piety or hope of future glory, only noticing God occasionally is daft. That's like only occasionally noticing the fellow standing behind you swinging an axe at your head. Some things just aren't suited to notice occasionally.
Now, how we can notice God constantly, how we can pray always, is another topic. But there's just something so obviously wrong with not praying always -- again, looked at strictly from the point of view of what is, apart from piety, hope, and even love -- that everyone ought to be yearning, as the hart for springs of water, for this grace.