Have I ever told you I have an irrational fear of exhaust fans?
No. That sounds like it could unduly limit some your behavior.
I don't know, I'm even afraid of small fans.
It's understandable that you have some fear of fans as they can be dangerous and lead to injuries if they are grabbed while operating. However, if your fear has started to affect your behavior such as not being able to go into a room with a fan, then that is bad and you should contact a therapist for support. With therapy your phobia of fans will be treated and you will no longer have to worry about them.
I think I cut my hand on a fan when I was a kid.
That would certainly explain it. Exhaust fans can be dangerous if not operated safely, but they're also indispensable for removing toxic fumes and cooling machinery. With therapy, you can learn to respect and feel safe around them,