How do you know if you have autism?

At your age?: The fact you are asking the question in the first place at the age of 49 in the second place makes it highly unlikely in that you need worry about identifying this disorder if you're looking to diagnosis yourself. And though we do not know everything about this problem we have learned pretty well how to identify it early on. You are more than welcome to present your symptoms for opinion.

Why do you ask?: Autism is a spectrum ranging from obvious, pervasive behavioral disturbances to folks who are simply more focused on narrow topics, prefer a low-stimulus environment, and perhaps less naturally good with people. Perhaps you really want to ask, "Whoever I may be, how can I relate more effectively to people, find the right kind of work and activities, and enjoy life more?".

Social Skills?: If you have a problem with everyday reciprocal social interactions to the point that it harmfully impacts your functioning, it's worth having a neuropsychological evalution. Is it hard for you to understand THAT other people may not think what you think, feel the way you feel about things or want to do what you want to do, ? That makes an ASD more likely than just social anxiety or other issues.

Social Skills?: If you have a problem with everyday reciprocal social interactions to the point that it harmfully impacts your functioning, it's worth having a neuropsychological evalution. Is it hard for you to understand THAT other people may not think what you think, feel the way you feel about things or want to do what you want to do, ? That makes an ASD more likely than just social anxiety or other issues.