Thinking about the future is pleasurable, and sometimes we’d rather just think about it than get there. Some events are more pleasurable to imagine than to experience.

We like to daydream because the mere dream itself can be a joy.

The main reason why our brains simulate the future is so that we can control the experiences that we have. 

Our brains make predictions incredibly quickly and about nearly everything in life. When our experiences don't match what our brain expects, we feel surprised.

The greatest ability of the human brain is to imagine, to see the world as it has never been before.

But imagination has three shortcomings:

• Imagination tends to add and remove details, but people do not realize that key details may be fabricated or missing from the imagined scenario.
• Imagined futures (and pasts) are more like the present than they actually are (or were).
• Imagination fails to realize that things will feel different once they actually happen—most notably, the psychological immune system will make bad things feel less bad than they are imagined to feel.

The word "happiness" is used to refer to three related things:

• Emotional happiness
• Moral happiness
• Judgemental happiness

It’s hard to define emotional happiness, but when we feel it, we have no doubt about its reality and importance. Because we have a poor recollection of our experiences, we cannot objectively compare a previous state of happiness to a present one.

All claims of happiness are subjective. And are formed from the perspective of a single human being whose unique collection of past experiences serves as context.

Nobody really knows what happiness feels like for others, so that means we can’t say definitely whether someone in a situation that might seem bad to us is actually less happy than we are. In fact, it’s entirely possible they are just as happy or even more so.

Not knowing what we are missing is the very thing that allows us to be happy despite not having some other opportunity.

Your experiential background can dramatically change your happiness levels.

Once you know something exists and have experienced pleasure from it, then your definition of happiness changes compared to what it was in the past.

Negative events affect us, but not as long as we expect them to. When our psychological immune system is working, we are able to cope with any negative situation that comes our way. 

Explaining events robs them of their emotional impact because it makes the event seem more likely. This allows us to stop thinking about them.

Wealth increases people’s happiness after it removes them from poverty and places them in the middle class.

After that, there is little relationship between wealth and happiness.

Experience and awareness are closely related but not the same.

Experience refers to partaking in an event.

Awareness refers to being cognizant that an event is happening.

It happens when a phenomenon arises from very large numbers of something but not smaller versions of it.

For example, billions of neurons lead to a conscious human brain, but two neurons are not a small version of consciousness.

Psychological sciences will always be imperfect because we are trying to observe someone else's subjective experience, but it's the best we've got and the closest an outside observer can get to understanding the inside of someone else's mind.

It refers to judging historical events or people by modern-day standards.

It is largely useless and unfair because you can't expect historical figures to make the same decisions as we do now because they lived in a very different context.