1. Evil is within us. It's a good idea to keep this mind in order to try to check yourself from accidentally slipping into some unfortunate behaviour. Often it's happening on a mostly subconscious level so you really need to be somewhat introspective.

Jealousy. Passive aggressive behavior (i was just being funny!). Objectifying women (the goal isn't to make them like you so you can have sex with them). Recognizing the real motivation behind your actions (i just want to show them I'm better than them). Etc. We all do negative crap without realizing it. Keep an eye on yourself.

2. There are some people who are really quite terrible to others. This is generally because they have failed quite badly at the previous point.  They will for example dislike someone because they are jealous of their good looks and happiness. But they want to think good thoughts about themselves and recognizing that they're being jealous would make that difficult. So they convince themselves that there is some other legitimate reason why this person deserves to be treated badly. For example they will decide the person is a narcissist.

Be wary in particular of people who seem to think that of others (that others are narcissists). It seems to be the default when someone really wants to dislike someone and they can't come up with anything better.

Some people have inferiority complexes. They will be consumed with feeling that someone else is better than them. That other may be very easygoing and nice yet in their mind any interaction with them is a competition where the goal is to make themselves look good and/or the other person look bad. This can lead to all kinds of bizarre behavior. Meanwhile they may be nice to someone else who they don't feel inferior to.

3. If someone treats you good that doesn't mean they treat everyone good. They may just find it in their personal interest at that time to have you on their good side. They might be treating others terribly at the same time. And. Tomorrow they may start treating you terribly too. Pay attention to what others think of them and for that matter, what they think of others. Because you don't want to waste years of your life on someone who ultimately is going to turn on you.

4. Dishonesty: Good lord but there's a lot of it going around. Don't be annoyed if some woman dumps you without explanation. Women are the physically weaker sex and this means they are more afraid of what might happen if they tell some guy the truth. They might just not want to date anymore because the guy has a little penis. I'm sure some women have honestly told a guy that and been beaten to death for it. They might not actually even know why. Just have some subconscious feeling if wrongness.

It is understandable to be highly annoyed if you were dating or friends with someone for many years and they just drop you without explanation. Please never be that person. People do such things mainly because they lack self awareness. They don't know why. Or they are jealous and convince themselves it's some other reason. That you did something so terrible you don't deserve an explanation. Or whatever. People are amazing at convincing themselves of things that make them the good person and you the bad.

5. Sometimes doing the right thing means going against the crowd or against someone who has some power over you. For example both my biological mother and father are now married to people who want them to have nothing to do with you. This is highly immoral. And both are weaklings who do as they're told. Why exactly for each is complicated but ultimately they are weaklings.

It's important to understand that to really be a good person there are times when you are going to have to be strong. When doing the right thing will mean people getting angry with you.

6. People can pass on their genes better if they commit adultery or just jump from partner to partner. The mindset it takes to do this isn't so great. Such people lack self awareness in so many ways and they do pass on their genes more than others. Their children usually have the same issues. And so it goes.

7. Often you will get this man who believes that he is in charge and everyone else in the family must be obedient to him. For every such man you will find a simpering women who only exists to please him and do as she's told.

Both disgust me. As such men couldn't exist without such women to support their "reign". I believe in equality. And so I have always liked "strong" women.

But the difference between a strong woman and a bossy or bitchy woman can be hard to see. So I have often had relationships with "bossy" woman. But I'm not actually a person that can be bossed around. So i have had quickly failed relationships.

Sociopaths. Someone said everything is a competition to them. A longtime friend it seems claim to believe.