I'm about as strict of a realist as they come. I'm notorious for offering pessimistic responses to people who share big ideas and plans with me. It's not because I want to be negative; on the contrary, it is because I think that every idea needs to be held over the flame of reality to let the fluff burn off. That's who I am by nature, but our nature is rarely the right place to be. Instead, what I try to do is take frequent opportunities to flex my own "dreaming muscles". I do this with my wife frequently. We'll go out for a drink at our favorite restaurant and have a long, honest conversation about what we are hoping to do in the future. These conversations are some of our most favorite moments.
Dreaming is healthy. Dreaming helps us set goals. Dreaming is the equivalent of checking the map to see how much farther we have before we reach our destination. Without dreams, we settle for less.
Be a realist, please. Ground your ideas within a clear understanding of what you can afford in terms of time, finances and energy. But please, check the map from time to time. Dream up a goal that you can work toward. It can only take you places you've never been before.