Well, as I read to process the elegant quote as appended below, I must say, Dr Maxwell Maltz was absolutely right!

“The most liberating of all thoughts is disregard or “disconcern” for what other people think.

Famous mail-order impresario and entrepreneur J. Peterman wrote (in his autobiography Peterman Rides Again); “Once you realize that most people are keeping up appearances and putting on a show, their approval becomes less important.”

Excessive concern over what other people think inhibits personality more than any other factor.”

My perennial favourite counter-measure against any negative opinion is applying my adaptation of the popular NLP Swish Pattern.

I visualise, in my mind's eye, with vivid colours and the sensory impressions of sights, sounds and even smells of the person spewing the negative opinion (placed in a bubble).

First, I increase the image size of both entities in my visualisation, and gradually shrink them down to teeny weeny size, and then I blow them up into splintereens, in the tradition of special effects of a Hollywood blockbuster!

It works for me all the time!