> Also, it is known thing or are "trains" a euphemism now like "friend of Dorothy"? I meant it only as a reference that one of the common characteristic sympto

> Also, it is known thing or are "trains" a euphemism now like "friend of Dorothy"? I meant it only as a reference that one of the common characteristic symptoms of autism is a deep focus on some topic of special interest. In boys with autism, trains, cars, or other machines are a common one.