Another nice TED talk, this time on insights on psychology from brain studies. Here is a summary.
We were not built to be happy, we were built to reproduce. We can be romantically in love with someone, attached to someone else and connect with someone else.
So we must build our own happiness.
Here is an interesting example of male-female differences mentioned.
Women tend to look at each other when intimate because of their relationship with babies.
Men tend to face their enemies, and stand by their friends, because of their hunting-fighting background.
And an older talk, where at min 17 she mentions that lust, romantic love and attachment are controlled by 3 systems in the brain that do not necessarily need to concern the same person. So we are not made to be happy.