I don’t know what cascading chemical awesomeness is going down in my brain when it detects and rewards me for the act of building, but I’m certain that the hormonal cocktail is the end result of millions of years of evolution. Part of the reason we’re at the top of the food chain is that we are chemically rewarded when we are industrious – it is evolutionarily advantageous to be productive.
And we’re slowly and deviously being trained to forget this.