Talking about a mistake you made

I completely misjudged my new manager. On his first day he was very quiet, and I jumped to conclusions , assuming he didn't care about the team. I complained about him to a colleague, and it got back to him. In hindsight , he was just nervous and finding his feet. Once I realised my mistake, I knew I couldn't brush it off and pretend it never happened. I decided to own up to the whole thing and we