Well, a possible story for the--for why you became afraid of dogs is that one day a dog came up and he was a neutral stimulus.
好吧，关于为什么你害怕狗的一个可能的故事是，有一天一只狗出现了，他是一种中性刺激。
英语百科
Neutral stimulus
A neutral stimulus is a stimulus which initially produces no specific response other than focusing attention. In classical conditioning, when used together with an unconditioned stimulus, the neutral stimulus becomes a conditioned stimulus.