The thing is, we in Europe are a bit spoilt, we have hardly any venomous animals here (at least in Central and Northern Europe). My arachnophobia isn't due to fear of being intoxicated.
I would be shocked if I had a snake or a rat in my room as well but it is different, a snake or rat doesn't give me the same sensation of disgust (and it would happen rather seldom), I can look at them without getting goosebumps. I can look at centipedes and millipedes but spiders.. their underside is the most repelling thing for me. I have a bit less problems with Daddy long legs, that are no spiders (Opiliones).
It's the legs, the body, how they move, how fast they get. And they always come to me, don't ask me why. I woke up with a spider in my eye. Spiders that come down in front of my face (multiple times), spiders that are besides my bed or on their way to it. It's a one sided love, it seems
It's ok for me when they are outside (still don't like sitting somewhere and suddenly I have spiders all over me, but that's the risk) but inside, where I sleep, NO!
Lydia made the biggest fuss about spiders in the shed, didn't see actually one, was inside half a second, left without switching the light off and shutting the door. Yeah, leave the door open.. that will help. She really wants the green house only for pics. There is no way she will be in that thing daily.