Is someone being an asshole to you? Ignoring you? Hurting your feelings? Making your life difficult at work or at home?
Well, here's a handy chart for figuring out when that thing the other person is doing/not doing is really because of you, or because of them.
I call this the 90/10 rule, for the percentage of the time that someone else's action or inaction is about them, and the percentage of the time it's about you.
The other side of the coin, of course, is that when you're doing stuff to others or attributing thoughts or feelings to others, it's about you, not them. So sometimes you're actually the "them," if that makes sense.
I keep a business-card sized laminated copy of this in my wallet at all times, because the 90/10 rule is probably the hardest rule in the world to remember. Nothing makes me more miserable than breaking or forgetting this rule.
Trust me, it's super helpful.