I am wondering if there's a term in psychology for a situation where you want something really bad, but you are not able to get it for the moment (or a goal that you are not able to achieve) and when you eventually do achieve the goal or get that "thing", you feel unhappy, it's a really bad feeling because you're maybe too late on something.
Here are two case scenarios that might be unrealistic, but I'm sure you will get my point:
1st case scenario: your dream is to buy a convertible car to go to the beach with your college friends, you spend 10 years saving for that car, and when you buy it you realize you're not in college any more and all your college friends got married, now you're not happy and have this bad feeling in your stomach; you wish you had the car 10 years ago.
2nd case scenario: a new gadget is released, all your friends buy it and mess with it, your dad tells you that he will get it for you next year when you get good grades (or for any other reason). Next year comes and you got good grades, your dad gets you the gadget, but nobody is talking about it any more, you're still unhappy although you have the gadget.