We do that too. As someone once said, "why should I ask for stuff if he's already got me covered?" The answer was, "he likes it when we ask".
Our daily asking and daily receiving is our way of honoring his authority and done in the vein of "give us this day our daily bread".
You see, I believe that every human being enjoys the exact same lifespan. And we even have a word for that life span: Today. As Paul said, "I die every day". For us, every day is a new day. The old has passed away. It can be learned from, and the future can be planned for, but our actual life is "today". And the question to be asked every morning is, "Today is my life. What am I going to do with my life?"