As to happiness, I am not so sure. Birds, it's true, die of hunger in large numbers during the winter, if they are not birds of passage. But during the summer they do not foresee this catastrophe, or remember how nearly it befell them in the previous winter. With human beings the matter is otherwise[...]every human death by starvation is preceded by a long period of anxiety, and surrounded by the corresponding anxiety of neighbors. We suffer not only the evils that actually befall us, but all those that our intelligence tells us we have reason to fear. The curbing of impulses to which we are led by forethought averts physical disaster at the cost of worry, and general lack of joy. I do not think that the learned men of my acquaintance, even when they enjoy a secure income, are as happy as the mice that eat the crumbs from their tables while the erudite gentlemen snooze.
--Bertrand Russell, "Ideas that Have Helped Mankind," from his book Unpopular Essays
(I'm not trying to brush off animals' suffering at starvation; it's his general point that I agree with.)
The underlined sentence is a little awkward, but what he's saying is: forethought makes us curb our impulses.
(I underlined it because I like the point of the sentence, not because it was awkward.)
Also, on an entirely different note, it has come to my attention that some people think that I have a cat because I cannot at this moment have a dog. This is blatantly untrue. I have a cat because there was a friendly, flea-infested kitten living on my back porch in December, and I have been conditioned by either my environment or my biology to want to take such things inside, bathe them, and give them a warm place to sleep. It is about as simple as that.