Asteya

After satya is asteya, or "not stealing." As with the other yamas, this principle isn't so much a technical thing, like a "don't shoplift!" commandment, but rather a principle that applies to one's general attitude. So, of course stealing money from someone would be harmful to them, but also taking credit that hasn't been earned is just as bad, however intangible. In an even more intangible way (and this seems more a subtlety that shows the translation isn't quite 'steal,' I think), we can 'steal' from our selves in a sense when we don't act to our fullest potential, out of laziness or otherwise, by losing that opportunity and that virtue.

Interestingly, another book I'm reading right now, which has absolutely no overt connection to yoga, actually has as one of its underlying principles something like asteya. Whereas the (financial advice) book encourages an attitude of abundance, that is, approaching life with the attitude that there's more than enough money to go around, turning asteya internally towards one's self means finding those unconscious impulses towards the converse, but in all manner of areas. It's an easy feeling to drop into that there's not enough love to go around, that a loved one will not give back as much as we give, or to give in to an impulse to hoard and cheat to feed greed. With asteya as a principle turned on those impulses, a more positive feeling and attitude of abundance is cultivated, which is helpful instead of harmful to others, and makes for less stress and anxiety on the part of oneself.
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somewhat relatedly, though out of context, an interesting passage by an old professor:
"The nice thing is that once I saw this, I was able to completely relax about my colleague, who I didn't want to feel envious of. Because, let's face it, to call someone an 'asshole' or a 'helicopter parent' or a 'slut' or a 'narcissist' is always to indicate the wound they create in you by being who they are, the vulnerability established by the possibility of your choices or your abilities being somehow not enough. (Conversely, the 'idiots' on the other side of the equation make us feel better about ourselves.) "