Regardless of how irrational his fears are and how well he knows they are irrational, he is still expecting to be humiliated. How this man is treated will make or break his opinion of libraries. Treated poorly, he may never again grace the face of a library. Treated well, he could well become our best source of public relations. I say all this to illustrate a point.
Patrons are normal human beings and have real problems.
Do your best to see the other side of every library transaction you make. In conclusion, I'd like to suggest an experiment you can perform. Make a list of a few fairly difficult reference questions. Note throughout the transaction how the librarian acts and responds. What do you appreciate about their service and what do you dislike.