It's another way that social anxiety manifests, as a lower level filter. It's how mine generally shows up, and used to be much worse before I did a bunch of therapy.

One thing that made this being anxiety based very clear was that one night I took phenibut for a party, and the following morning it was still in effect and I found myself thinking of way more jokes and doing little improv reactions to the people I was talking to. It's like my brain was completely filtering them out due to very low level anxiety. I got lucky and the effect partially persisted afterwards, because it taught me that saying these things was safe, so I didn't have anxiety about them afterwards.