Thanks OP :)
Our brains are wired to crave progress bars. We want that next goal so we can track our progress and fill it. We want to fill those bars as fast as possible, missing out on so much as we focus on getting to that next goal.
True happiness comes from a sense of contentment with your world. It comes from accepting things come what may, and not dwelling on externalities and mental constructs like "milestones". Every day is a milestone.
Very true @proggr contentment is a key to happiness and many people fail to realize this.