How complaining hurts you

The only idea I keep trying to remember and apply repeatedly is: Stop complaining because nobody cares, Take action if you want to change the situation, and Understand incentives to give rewards when it's needed and cause pain when it's needed.

Life is unfair, but when you complain about something or someone, you are giving them the power to decide the life you will live. It might be a government, a boss, a software bug, a tax law, a parent, a teacher, or anything.
You only keep that power by taking action instead of complaining. Your action doesn't have to be positive, it does have to be pragmatic.

If your government is corrupt, instead of complaining about them in a coffee shop, either organize a movement that causes them real pain (e.g.: Arab spring), enter politics to make change/gain more advantages, or work hard to leave the country.
If a client doesn't want to sign a deal with you, instead of complaining, understand their needs and concerns, tackle them, and make it unreasonable for them to not sign the deal.
If your parent is hurting you in some way or another, go live somewhere else and work in a restaurant to sustain yourself instead of complaining.
If you think your company underpays you, build in-demand skills, ask for a raise, and leave if needed.
If your high-quality content doesn't generate enough views, instead of complaining about the algorithm or how stupid the audience is, either keep increasing the quality until you're so good to be ignored, change your target audience for a smarter one, or just stop and go do something else.
If you're a student and think school is useless, instead of complaining each morning in your class, either leave school and go work in a restaurant to sustain yourself, or just shut up and keep studying because you believe the pros outweigh the cons.

Sometimes you can't change something that happened in the past, but you still can reframe how you see it and take actions about it in the present.
If you had a tough childhood, you either use it as an excuse to not do anything and complain about your bad luck even though nobody cares, or you can go to a therapist, or you can just stop thinking about it and complaining because other people with much worse childhoods achieved more than you.
Instead of complaining that your kids are holding you back, maybe have them as a motivation to achieve more.

Bottom line: Nobody cares about your complaining, Take action and Understand incentives.