You see, most creative professionals are profoundly unhappy people. This is because the equation for happiness is usually easy - your expectations have to be lower than your achievements. As a side note, this is why the renowned mid-life crisis happens, because that's the point in your life when you realize that many of your dreams are impossible.
But going back to creative professionals - our expectations are off the chart. It's because we've been taught that we can achieve anything, with our imagination being the limit and hard work being the currency. It's because many of us come from families of high achievers. Yes, we are profoundly unhappy because our expectations are usually much bigger than our achievements. This is the reason for why many of us are idealists, for why we want to change the world. Many of us are also atheists, but all of us want to achieve some form of immortality, therefore that's the reason for why many of us want to build things that are long lasting.
I used to say the same things as you did. You may not feel the above right now, I'm going to make the assumption that you're in your twenties, which means you've got the energy to be hopeful about the future. But take it from a 32 year old that is going through a mid-life crisis 10 years earlier (or maybe it's just a burnout episode, I don't know), but this youthful energy is going to dissipate and you're then going to feel the emptiness in your life. And I'm lucky, because I have a wife and a 4-year old whom I love very much and which represent my reason for getting up in the morning.