Assistant in a shop I regularly go in: You don't bring your son in here anymore. Has he just reached the age where he no longer wants to go shopping with dad?
Me: Yes. He's 17, almost 18 in fact.
Shoppie: Is it weird having an 18-year old son?
Me: No. I mean, it's not like I just woke up one morning and he was suddenly 18.
Shoppie: No, I suppose you've had 18 years to get used to it.