Do people on the autism spectrum recognize other people who are also autistic?

Me and a buddy were at a bar drinking, and we were talking and I forget exactly how the conversation went but he was saying something about him being autistic and having adhd and some other thing, and I had mentioned I have never been diagnosed or tested or told if I have any mental thing like that, and he said autistic people recognize autistic people and click with each other.. is this true?