It's not the first time it's happened to me. Right now I can probably think of 5 men outside of family (who genuinely wanted to teach me pool as i had my first game as soon as I could see over the table) who just kinda point to the side with 'hit it here and it will ....'
Last night I was happily playing with my colleague (female) after a long day working away. My new (male) boss came over to give us 'advice'. We're all playing fairly well and he feels the need to 'help'.
I played him afterwards and ironically beat him with five balls left on the table.