It's funny. After spending a week thinking about what makes me happy, what makes me sad, and why, some people start to feel very selfish.
Especially people who have been raised in certain religious backgrounds where "being selfish" is one of the 7 deadly sins because we are supposed to "pick up our cross" and be mostly miserable through life (I guess that last part was my interpretation).
Interestingly enough, I would argue that the Bible doesn't have much to say - if anything - about selfishness. It does talk about pride, arrogance, greed, sure... but I'm not sure it's got much to say on selfishness.
Because we're all selfish. If we weren't, no one would be interested in even talking about what any religious text says or does not say. But we are interested because we believe those texts have something to say about a good life of some kind. Or worst case, heaven. Which is very selfish too - it's just future selfishness passed off on to some other life so that we can be selfless here in this life to get what we really want later.
If we ignore the religious texts, of course, we're selfish too - because we think that it's a better life to ignore them.
So, we're all selfish. We want what is best for us. If we didn't, we wouldn't read, grow, change, evolve, move, improve, work-out, create, or much of anything, honestly. It's self-love. It's good. It's necessary.
The danger comes in the next step.
After self-love comes other-love. That's where the beauty is. But we can't have other-love without self-love. And self-love without other-love is just greed, pride, arrogance, and, you know, those things that, selfishly, none of us want.