How I know I am old

There is this tv commercial running lately. It's for a cell phones or maybe for cell phone service. I'm not sure because the commercial content itself distracts me so much I pay no attention to the logo.  It shows 2 people, one sitting outside on a park bench & the other sitting in a home, on a sofa. They are both holding cell phones and texting one another what are assumed to be romantic messages, given the doodles shown over their heads.  Here is why I don't know what exactly is being sold & why I do know I am old. Every time I see that commercial I cannot help but say "Why don't they just CALL each other? They are holding PHONES in their hands." Obviously they have nothing going on to prevent them from actually speaking to one another. They are alone. They are not doing anything else.  Why would you text someone in that circumstance? I can see texting if you are someplace where you cannot talk easily - someplace really noisy or someplace really quiet. I can see texting specific information that doesn't require extraneous conversation - a phone number, the amount the parking fine turned out to be. I can see texting useful or important info if you know the recipient is not in a position to take a call - in a meeting or at the dentist.  But why, why why why, would you carry on a random text based conversation with someone when you are both sitting alone, doing nothing and HAVE PHONES IN YOUR HANDS?? I can see the usefulness of texting, I can even see the fun in randomly texting your significant other affectionate messages, I can even sort of understand texting 'what up?" to your friends but I don't understand the need to fully converse with it.  I don't understand why the recipient of 'what up" would text back lots of info that would then be replied to with more info. Why wouldn't the recipient just call back?

So, obviously, I am old.