George Thorogood first sand those words back in the 80's but it doesn't matter when because talking too much has been an issue for human beings since the day some ape-like being uttered their first words.
When you are in front of your customers, sometimes you talk too much. When you make sales calls, sometimes you definitely talk too much.
We all do it. It's human nature. We all love to talk and our favorite subject is usually ourselves. However, talking too much and especially about yourself is a mistake you can learn to make less.
In the words of the great Dale Carnegie,