I haven't learned very much in my years on this planet, but I have learned (the hard way, of course) enough to know there is a land mine inside this excerpt from an Economist article:
"Americans expect a lot from marriage. Whereas most Italians say the main purpose of marriage is to have children, 70% of Americans think it is something else. They want their spouse to make them happy. Some go further and assume that if they are not happy, it must be because they picked the wrong person."
Another person cannot make you happy. Let me repeat that. Another person cannot make you happy. It is trite to say (annoyingly, most truths are), but you have to find happiness inside yourself.
On the other hand, another person can make you miserable.
In my observation, there are two basic sets of people: 1) those who are naturally happy unless especially bad things are happening to them, and 2) those who are naturally unhappy unless especially good things are happening to them. If you're one of the former, you don't need to look for someone else to cheer you up. You’ll be just fine whittling on the porch by yourself. If you're one of the latter, no one else ever will supply you with enough good times to keep you smiling. Attempts to extract enough out of your companion merely will add to you own disappointments while making him or her miserable.
Type 1s almost always marry type 2s. Type 2s almost always marry type 1s.
Said Oscar Wilde, "I always give away good advice. It never is of the slightest use to myself." So, here goes. Just try to find someone who doesn't make you miserable. At least he or she won't get in the way.