Everything I want... well, I think the world would be wholly different. I want God's will to be done. I want the Kingdom of God on earth. I want peace and love. I want an end to human-induced suffering and poverty.
I hope I can handle it, since I believe this is eventually what will happen. I may have to die to get to it, but ultimately that's just a transition.
As for more temporary desires...
I think I either already have or could have everything I want in this lifetime, with the one exception that haven't enough time to travel to as many places as I'd like, meet as many people, or learn as many things. You know... mortality does have its limitations.
In terms of material possessions, I have tons more than I ever had as a child and I don't really want any more. Sometimes I feel like I'd rather give away about half my junk and that might make me feel better, like my living space was more peaceful and aesthetically pleasing. My house is pretty small and I don't have that much stuff compared to some, but it still feels like a lot to me.
About the only material thing (if you call them that- I don't really consider animals possessions but rather non-human people) I ever desperately desired was a horse, a dog, and a cat. I have all three, and then some.
Other than that, I just want the basics: decently good health, loving relationships, a roof over my head, time in the mountains and woods, and food. I have all that.
I'm blessed.
I do want children, but I'm completely fine with adoption and want to do that whether I have my own or not, so no matter what, if I am diligent about saving up for it, I'll have that as well.
If I won the lottery tomorrow, outside of owning a cabin in the woods rather than renting it, life would not change much. I'd still work, though I'd do it for free. The rest would get passed on to others and charities. I just really have what I want already.
Now, is there anything I want and couldn't handle? Yes, sometimes.
Ever since I was a little girl I've had times that I've wanted to give my entire life to spirituality- to be a nun or somesuch. There is often a push-pull between my desires for a relatively ordinary life (husband, kids, pets, education, science, etc.) and my desires to give over my entire life to a monastic type one, devoted entirely to service and worship.
Ultimately, at least in the here and now, I can't handle that. And I am not an "I," but rather a "we" since I'm married. I think God has His reasons for that, and perhaps the lessons I most need to learn and the areas I most need to grow spiritually are best addressed in the challenges I face as a person in a marriage, a regular job, and a regular life. I know at least with my marriage that I've learned a ton spiritually that I would not have learned if I did not have that kind of relationship. Lessons in humility and forgiveness come to mind...