Why is the grass always greener on the other side?

Some deep questions I have about life.
Why is the grass always greener on the other side? Why does every choice seem to lead to suffering? It's like when you make a choice, you find yourself wishing that you had made the other choice!
For example, if you are single, you will long for the love, companionship and stability of marriage and committed relationships. You will often feel lonely, like no one really cares about you or is there for you.
But if you are married, then you long for the freedom of being single and feel like a caged bird with obligations and responsibilities, unfree to meet other exciting women and develop new connections, or pursue your passions.
If you are a perpetual traveler wandering around the world, after a while you may long for the stability of a home, family, routine, stable friends, etc. But if you have a normal stable routine life, then you may long for adventure, new experiences, freedom, seeing new lands, etc.
Or, take these simpler examples:
If you stay home too long, you will feel bored, like you need to get out and have some fresh air and move around. But if you are out for a while (esp if you are an introvert), you will feel tired and miss the comfort of a cozy home. Isn't that weird?
If you stop eating junk food, you will crave it after a while and miss the flavor. But if you stuff yourself with junk food, then you will feel guilty and wish you hadn't. At that point, you will realize that staying healthy and not eating it would have been better. But if you hadn't eaten it, then you would have felt the craving for it! So either way, you lose and suffer!
It seems that whatever choice you make leads to suffering. Why is that? Is the universe playing some cruel trick on us? Are we meant to suffer and crave and feel dissatisfied?
Why is the grass always greener on the other side? Why does the grass on the other side always appear to be more desirable? Why do we always regret the choice we didn't make?
Is this what Buddha meant when he said that "the nature of life is suffering?"
Why is the grass always greener on the other side? Why does every choice seem to lead to suffering? It's like when you make a choice, you find yourself wishing that you had made the other choice!
For example, if you are single, you will long for the love, companionship and stability of marriage and committed relationships. You will often feel lonely, like no one really cares about you or is there for you.
But if you are married, then you long for the freedom of being single and feel like a caged bird with obligations and responsibilities, unfree to meet other exciting women and develop new connections, or pursue your passions.
If you are a perpetual traveler wandering around the world, after a while you may long for the stability of a home, family, routine, stable friends, etc. But if you have a normal stable routine life, then you may long for adventure, new experiences, freedom, seeing new lands, etc.
Or, take these simpler examples:
If you stay home too long, you will feel bored, like you need to get out and have some fresh air and move around. But if you are out for a while (esp if you are an introvert), you will feel tired and miss the comfort of a cozy home. Isn't that weird?
If you stop eating junk food, you will crave it after a while and miss the flavor. But if you stuff yourself with junk food, then you will feel guilty and wish you hadn't. At that point, you will realize that staying healthy and not eating it would have been better. But if you hadn't eaten it, then you would have felt the craving for it! So either way, you lose and suffer!
It seems that whatever choice you make leads to suffering. Why is that? Is the universe playing some cruel trick on us? Are we meant to suffer and crave and feel dissatisfied?
Why is the grass always greener on the other side? Why does the grass on the other side always appear to be more desirable? Why do we always regret the choice we didn't make?
Is this what Buddha meant when he said that "the nature of life is suffering?"