Unfortunately, men seem to always want what they can't have.
They like to chase, but if they get you, they want to move on to the next big thing.
It's almost like they prefer the pursuit of happiness more than happiness itself.
This is why they have a tendency to stray more often than women. They have to aim higher than the woman they have already as they get used to home ground in a bit and need move on to the next challenge. They get bored of the same old moves. They need change.
Like a video game, Wife 1.0 needs to be conquered until she is conquered, then they wait for the release of wife 2.0.
They don't seem to understand that life is not a PS3 game.
So what is the secret to happiness in a relationship?
I'm going to bring in a HIMYM ref here where they talk about how in a couple, there's always a Reacher and a Settler. The Reacher thinks he/she has landed someone much better than what they deserve, and the settler feels that they have "settled" for whoever they chose.
I feel, for harmony in a relationship, the men should always be the Reacher and the women the Settler.
The men will not be happy unless they feel they are the "Reacher", because then they have something to strive for as they've landed someone "better than what they deserve". They will always try to make up for it by striving to keep the woman with them. So the game is, "keep the woman". The woman on the other hand, will be happy with the attention paid to her by her partner and as a woman needs nothing more than that from a man anyway, happiness will reign!
Disclaimer: I'm 28, and single. This is my theory, for now. Who knows what kind of changes life will bring! 10 years ago, I thought I'd fall in love and get married and that by 28 I'd have a kid and a dog and a house with a garden. God had other plans I suppose, and to tell the truth, I'm quite happy for it!