I can't think of any conceivable circumstance in which the banker's advice would be true.
The bureaus only store on your file what gets reported to them by the institution who extended you the credit. This reporting tends to happen at 30, 60 or 90-day intervals, depending on the contract the bureau has with that institution.
All credit accounts are "real" from the day you open them. I suspect the banker might be under the misguided impression the account doesn't show up on your report (become "real") until you miss a payment, which forces the institution to report it, but this is incorrect-- the institution won't report it until the 30-day mark at the earliest, whether or not you miss a payment or pay it in full.
The cynic in me suspects this banker might give customers such advice to sabotage their credit so he can sell them higher-interest loans. UDAAP laws were created for a reason.