Around the turn of the century (I have always wanted to say that) I was a Linux Migration Consultant. Client end encryption was my specialty. After 9/11 there was a seminar hosted by two CIA agents regarding social engineering and data breaches as it relates to corporate terrorism. I was asked to attend.
At one point, the female agent spoke about listening to your gut if someone's behavior felt off or suspicious. "If it looks like a duck, walks like a duck, talks like a duck, it may not be a duck but it sure as hell spends time with the ducks and may be influenced by them."
After the session I asked her to elaborate more on that. She told me that people are tofu and absorb the flavors around them. If you surround yourself with unhappy and joyless people, you will become like them over time. She explained this is why undercover ops are so psychologically gruelling. To not absorb the flavors around you.
Then she spoke of her marriage. She has been married for almost 30 years at that point. She told me that they almost divorced at one time. The reason? Everyone around them was unhappy. They were hanging with miserable and unhappy couples who did not believe in love and romance and the institution. "We were surrounded by unhappy ducks so we absorbed them and became them. When we started spending time with swans who were beautiful and positive...we became more like them and we believed again. We hoped because we were among the hopeful. We loved because we were with lovers. We laughed because we were surrounded by joyous laughter. It is not weak, it is human nature. If there is something you desire to be, spend time with people who are like that. If you wish to be positive and you are surrounded by negative people, it will always be difficult."