You need to adjust to different situations. Adjust to people. Adjust to their moods. So be flexible.
Don’t be so principled that you don’t see the negative aspects of your actions. You can’t be blind to the effect you have. So be flexible.
You might not like what other people say. You might say something that other people don’t like. So be flexible.
You’re on your own. It’s not going to be easy. So be flexible.
P. S.: Being flexible in bed should help too.