Money makes problems go away. That's nice. But when the problems in your life are gone, the remainder is not happiness. It's vacuum.
If life were a game, then getting rid of the problems is like skipping to the end, past all the obstacles. You have the entire map uncovered. You can travel any place, buy anything you want that in-game vendors are selling. You can complete all the little achievements - find all ten of this, kill all six of that. And it's easy; you have all the upgrades you want, and you can kill everything in one shot.
But it feels hollow, and shallow, and it's nothing like playing the story for the first time - with appropriate difficulty, where fights are a challenge, and you have to keep trying to win, and winning feels rewarding, and you're at the center of a story with dramatic turns, and you don't have the means to know everything yet. You can deprive yourself of the advantage - unequip your gear, try to kill everything with a knife in close combat - but you know such restrictions are arbitrary, and just as lacking in meaning as any other way. But you'll do that - because what else is there to do - and then that will be done, too.
Having all the money you want is like having your life in front of you, and it's already game over. You've already won, and that's in the past - perhaps it happened before you were even born. Nothing you do from here on really matters, and after you've explored the trivialities of the world, the only mysteries that remain are the hard ones, the unyielding stone walls imposed by nature; the borders of our known world, which no single man can realistically overcome, regardless of what wealth they have. What you can realistically hope to do is help chip away at eternity - contribute what little you can in the gargantuan task of expanding our world a bit more.
If you're in that spot, and have passion and love in your life, it makes all the difference. Money makes a good life better; but arguably, it is more worthwhile to have passion and love, and be poor, than lack that, and have all the money in the world.