Every single goal you have is just the next step on a ladder, as soon as you hit it there will be another one. You'll forget you even worked to get there, and focus on the next step, thinking "ah if only I were there, I'd be happy". It never stops, it gets increasingly harder and depressing unless you are aware of it. As far as I can tell a lot of people never understand that until very late in their life.

Most people in the world are living with way less than what you have, it's just a matter of perspective. If you think material things will help you feel better you're plain wrong. As long as you have food, a roof over your head and some sort of community you're good to go.