To wonder how one person an have such power over others actions?

[TheWhisker]

My former closest friend blocked me on social media and hasn't spoken to me since after I questioned him about him leaving me out of a night out.

Sine then, other mutual friends in our friendship group have blocked me or unfriended me. They won't reply to my messages, but my guess is he's telling them lies about what I have done/said. It makes me feel horrible inside that some untruths might be going around about me and makes me wonder what he's going to do next.

Why are our mutual friends listening to him without even hearing my side of the story?

Because some people are very believable and have charisma and charm that just wins. Justified or not, fair or not it’s the way of the world. People can be as nice as they like but it doesn’t make them a winner, harsh but unfortunately true.

Some can be good at public relations, or have more leverage, or others only appear to be on your side etc, then when it's war, it's a mix as to the turncoats, and loyalists etc