We don't have a dog, but our neighbours have two Miniature Schnauzers, and we're sort of foster parents. We look after them when their owners go away on holiday, or if they're away all day, and we see them every day, so I know them almost as well as the owners do.
Tikka is a bit neurotic, and she doesn't like different noises. We're in Spain, so we have fireworks going off most weekends, and that doesn't bother her. However, the first time she came into our house - about 4 years ago - our cuckoo clock struck just as she was going past it into the garden, and she was terrified. We couldn't coax her back into the house, and she had to go home through the garden. It was weeks before she'd even be in the room with the cuckoo clock, and she still takes the scenic route into the garden, rather than passing the clock.
Bertie is more laid back than his sister, but he doesn't like cold water dripping on him. Pat and Brian - their owners - live very close to the swimming pool on our complex, and I used to go in the garden for a drink after my swim, but because I dripped cold water over Bertie, he wouldn't come near me. Then I started going for a drink before the swim, but he still wouldn't come near me, as in his mind, I had a swimming costume on, so I was wet.
I didn't like upsetting the dog, so I stopped going in my swimming costume. I have long hair, which I usually keep tied back for coolness, except when I'm swimming. Pat asked me up there for some reason one day, and my hair was down, as it had only just dried out from the swimming. It wasn't dripping, and it wasn't even wet, but Bertie still wouldn't come near me, even though I was fully clothed. I asked Pat for a scrunchie, and as soon as I tied back my hair, he came for his cuddle!
This dog is up for a fight with a German Shepherd who always growls at him, and who could do real damage if he wanted to, but he's frightened of my dripping hair. Also, he doesn't like wasps, flies or other insects. He had a bad reaction to a wasp sting a couple of years back, and he's convinced that anything that flies is out to get him!