I've never been diagnosed, but I have felt "different" all my life, especially as a child. I was slow to mature, clumsy, bad at sports, had trouble in normal social situations, had intense interests in things that were outside the mainstream, especially solitary activities... I am 47 now, and though I have learned to engage in many more typical forms of social interaction, I always feel as thought I am "acting" normal, for the benefit of others. I often make a good first impression, but feel like the more people get to know the real me, the greater the likelihood that they will think I am weird and reject me. I feel like I lost a job due to having this problem. I am married, and the woman I am married to (I suspect) also has ASD, so we understand each other's idiosyncrasies and allow each other space. We don't have many friends because we are both so uncomfortable in social situations. I am chronically depressed (currently taking meds for this) and spent much of my young adulthood as a substance abuser to self-medicate. I have intense interests that I often pursue unwisely, and my wife has commented many times about how much I like to take things apart to see how they work. I have a tendency to talk too loudly, and often have difficulty stopping talking, even when it is obvious that other people in the conversation have lost interest or are annoyed with me, to the point of having lost friends over this tendency to "preach", sometimes in an angry fashion. This is a trait I share with my late father. This also manifests itself as a tendency to be pedantic, and I have been called a "know-it-all" many times.
I don't know if any or all this makes me ASD, but I know something is different about me, and it would be nice to finally know what it is after all these years.