The consistent, unproductive preoccupation with all the things we have to do is the single largest consumer of time and energy.
Think about the last three times you became upset about something in your personal life. It's almost a certainty that at least one of those situations was caused by the fact that your limits were crossed. You probably didn't articulate those limits in advance. For example, your neighbor comes over unannounced to chat. You have only a few minutes to spare, but you fail to tell your visitor. Out of kindness, you listen while your blood pressure rises as the neighbor talks for an hour.
-Michael C. Donaldson, Negotiating for Dummies
Again, bad attitudes are contagious. If the people closest to us, including family, friends, and coworkers, have negative attitudes, you may "catch" one as well.
Just remember, you don't have to get upset if someone is trying to make you upset. You can choose to stay happy and upbeat. I like to think of this as wearing a bulletproof vest. People can fire negativity at me all they want. But if you remember that it is their issue, not yours, it should bounce right off you.
- Tabatha Coffey, Own It!