The expectations we put upon ourselves or are put on us can be higher than what we can achieve - being moderately well off and intelligent in the richest country in the world makes it very easy to be a disappointment to yourself or others, despite whatever success you may feel - it will never ever be enough.

This is keeping up with the joneses, just instead of the shiny new TV its a more ephemeral "life experiences" and success. Now, with the internet you're not even competing against your neighbor, you're competing against the world. Guess what - the world is always doing something more interesting, being more successful, having more fun than what you're doing. HN in particular exacerbates this issue. For some reading about successes is inspiring - for others it just shows them how far of a gap they have to go.