Yeah same here I also am 20yrs old, but I don't know whether or not Im on the spectrum, so for now I will say Iam not; but I have a huge issue with assertiveness and "putting my foot down" as in being firm when I need to the most. I will not go into detail as it is too complex of an issue to explain; but my grandparents neighbor whom I have known for since I was five had explained to me that I need to be more assertive with people regardless of whether or not I will hurt their feelings as said people will put me on a guilt trip. And it is my passiveness and and fear of guilt that stops me from truely getting what I want and or need from my family and what friends I do have. Nothing manipulative as I think they're the ones manipulating me, but regardless assertiveness and some agressiveness is one thing that needs to be learned in life and it can and will take some longer than others to learn that including myself and whether or not one is or isn't on the ASD sprectrum.