I think it's too easy to become obsessed with achieving every item in the game. And then too easy to feel really unhappy when we don't. It's one of the worst psychological elements of the game.
Of course, that's been engineered in, to improve sales.
My advice is to recognize this frustration as the evil sales tactic that it is, and choose instead not to give into their manipulation.
Instead, play the game to enjoy it on your terms. Where you fit it into your schedule, not EAs. And if you don't get the last prize, it's not a reflection of your lack of effort. It's an indicator that you have a life filled with greater priorities, and that's ok.
Or you can succumb to irrational feelings of inadequacy and loss. I don't recommend that one