Heck, I would get retweeted by someone, and not even know it. I can never even keep up with who retweets and cites, or replies to whom on twitter even less than half the time?
This isn't just someone.

This is a decorated General who also was head of the NSA and CIA during his storied career.
Oh, I understand completely.

They don’t ordinarily respond to just anyone. You must have caught their eye just at the right moment with the right thing, at the right juncture on the topic with something.

You never know what their thinking?

But, it was something for sure.