Can you guess how old is a person who calls you on the phone?

Yesterday, a funny thing happened. After that I grinned by myself.
I got a cold call in the afternoon. It was she, and she solicited adding a solar generator on my house.

So I declined immediately, because our house was too old to add it.

But she asked me to respond surveys. I had enough confident to deny all soliciting, so I said "OK".
Well, well, first she asked me "how old is your house". So I said "It's almost 30 years old". I heard her disappointment.

And next she asked me "may I ask your generation? " So I said "I'm in my 50's".

She was """VERY""""" surprised.
She said " I'm sorry I thought you were in your 30's." (I don't know why she said sorry to me.)
And she stopped soliciting. (I don't know why? Probably she understood, if she continued, it couldn't be help.)

And the  conversation was done.
I was grinned.

Well, well, these days I often have cold-caller about "graves".
So I thought that if I said "I was in my 30's", a cold-caller would hang up immediately".