Froya wrote:
One reason why I don't think I can have friends or a boyfriend is that I'm VERY out of sight out of mind. It's scary. I haven't though about my stepsister at all almost for months

I haven't felt anything for her. I do however know that when I meet her my feelings will come back, they have started to now that I think about meeting her. I will have something to give.
I wonder why I'm like this, and what it is. I don't think it's autism related.
I think it
is autism related. I'm like this too.
It is very, very rare that I will miss someone or think about them when they're not there. Out of sight, out of mind, exactly as you say. It doesn't mean you don't care about them (the feelings come back when you see them next); I just think we live a lot inside our heads.
I was saying this to my dad recently. He and I can go a long time without interacting with people, and it doesn't really diminish how we feel about them when we see them next. But my mum and brother (neurotypical) seem to need top-up interactions all the time.
I don't think either approach is bad, just different.
Have fun in Oslo today