Let's suppose there are multiple levels of heaven. Would everyone want to go to the top level?
Getting into the highest level of Heaven isn't like getting seats on the 50 yard line at the Super Bowl, it's like being the quarterback of the winning team.
Would a high school quarterback enjoy going to the Super Bowl and sitting on the 50 yard line?
Would he enjoy playing in the game with the most elite NFL players in the world, trying to read the routes, thread the needles, and trying to evade 350 lbs linemen trying to slam him into the turf??
That is how people misunderstand heaven.
Heaven isn't a "one size fits all happiness."
Heaven isn't just a standard gift that can be given to anyone. They wouldn't enjoy it. There are "levels" or degrees of heaven. Like the Bible describes in 2 Corinthians 12:2 about "the third heaven" - there are different levels and parts, where each of us will be the absolute happiest and most comfortable.
Would you enjoy being on stage in front of thousands of musical theater fanatics to play the role of the Phantom in the Phantom of the Opera? Would that be amazingly awesome, or would it be humiliating, and the most uncomfortable experience of your life? Would you be very very out of place singing next to professional broadway singers?
Going to heaven is about being happy, and you will inherit the kind of heaven that will make you happiest.
What if you didn't make it to the top? Like someone asking me why I want to become a child psychiatrist making $150,000 per year.
"But you could have been a plastic surgeon making $400,000 per year. You could have been the medical director at the Mayo Clinic. You could have been more!"
If I never wanted those things, then I'll be most comfortable right where I am. I think heaven is the same way. We will know exactly what we could have had, but we'll be exactly where we want to be.