The trouble with walking around the house with a hammer in your hand is that, pretty soon, everything starts to look like a nail. In theory, theory and practice are the same. In practice, they're different. We regret more things we didn't do than things we did do. The future is that time when you'll wish you'd done what you aren't doing now.
Nothing is impossible.
Some things just haven't been done yet. Our eyes are placed in front because it is more important to look ahead than back. I've never seen a monument erected to a pessimist. If we keep doing what we're doing, we're going to keep getting what we're getting. First Yesterday's the past and tomorrow's the future.