I can't build credit if I pay it off Every month
He's right. You have to leave a balance every month. I use a credit card to buy gas, generally around $500/month. I pay it all off at the end of the month, minus around $30-40 to leave a balance. If you just pay it off every month it isn't getting reported.
That is what I was told by someone high in the banking industry. I'm sure you'll tell me how they're wrong.
Why would I do that?
I didn't know this.
*shrug*
I've heard this too and idk if it's true or not. I will tell you this... my wife is a super tightwad... she always pays our card off every month. It hasn't seemed to ever have had an adverse affect on our credit...
Of course, we have a mortgage, car payment(s), power bills, etc. that she's always been religious about... in the 18+ years we've been married she's been late on like two payments for something and one of those was an online error by our bank.
Here's some credit tips...
http://www.nerdwallet.com/blog/2012/easiest-raise-credit-score/
In general, if you have accounts in your name, and you keep them up to date and don't have late payments, your score will be fine.