Born in September?

I have been encountering texts on posters, T-shirts, and sweatshirts since around June that say, (paraphrased as they are not all consistent)
I am a grumpy old man
I was Born In September
I’m too old to fight
Too old to run
I’ll Just Shoot You And Be Done With It
my daughter/wife gave me this shirt/jacket/poster

There are variations in the text.
My question concerns the “September” reference. I have not encountered any similar reference to any other month in any other poster/sweatshirt/T-shirt. I am unaware (and cannot find) any reference to September being the birth month of old people, mean people, curmudgeons, or similar people. There are lots of places where traits are ascribed to those born in September, but they tend to be the usual list of “bright,” “romantic,” “leader,” “driven,” and similar, (or contradictory), traits laid on people from other months.
I have not found any literary reference to the whole quote.
As noted, it began appearing months ago, so it does not appear to be associated with something written to be published this month.

Can anyone identify the source for this text or explain the September reference?

Tom, do you have a September birthdate listed on Facebook?

These t-shirts are printed on demand with text that’s harvested from your profile. I once saw an ad that compared “Other People” (a picture of a boring horse) to “Assistant Professor of Economicss” (sic) (a dabbing unicorn). Guess what my job title is.

That could be it. I do have a September birthday. I do not make an issue of it or publicize it, but it may have been picked up when I first logged on to Facebook (to track my then teenage daughter). (And we certainly know how secure Facebook has been over the years.)

Although I have a birthday in September, I haven’t seen an ad referencing it. I do get various ads targeted at grumpy old men, though. They’re about the only targeted ads I see that are appropriate.:wink:

I’ve had the same thing happen with my surname - had random T-shirts advertised to me ascribing particular characteristics to people with my surname.

It worked about as well as a random plug-n-play slogan might be expected to work. They didn’t get my money.

I’m a September kid and I’ve never heard of the OP’s text before.

I am pretty sure that Ace309 nailed it. After his post, I actually had a target advertizer, with whom I have never interacted, hit me with an offer that promised to deliver several personal items including a reference to my birthday. Our only common reference is through Facebook.

Being born in September means your parents were gettin’ busy for Christmas.

I was born on Sept. 1, and although I never asked my parents, I have long suspected they had a particularly nice New Year’s Eve celebration.

Sep. 9 here, never heard of this before.

All great people are born in September.

I just received an email offering me the opportunity to resell T shirts with branding bearing my name… except the person (probably a bot) that sent them to me seems to have assumed that my name is ‘MANG’ (it happens that the human readable name on the mailbox is Mange Tout - related to my username here - although not sure how they decided only to use the first 4 letters of that).
Look at the lovely MANG T Shirts I could be selling!

Why, thank you.