If somebody is trying to school you, and if there is a reason to believe you work in a genius-factory, then its ironic that the school-er doesn't do their homework into the school-ee to understand what they might be doing.
Sounds like someone mentioned how awesome a Lisp is. Ironically he said to someone who has done a bit of Lisp before. There ain't much to the OP story, or at least he hasn't divulged that much, but the song he wrote is pretty cool.
1) he knew he did LISP like languages and wanted to share
2) he didn't know he did LISP like languages and wanted to share
3) he was showing off.
4) the other choices.
I went to 3) based on my 40 years experience in computer science.
Maybe he just didn't recognize his face? Or might have recognized the name but lacked knowledge about his career? Remember Hanlon's razor: "Never attribute to malice that which is adequately explained by stupidity." Or, more politely and from a different angle, don't assume that the collection of facts that you happen to be aware of is obvious to everyone.
Go back to school?