Keep your senses open. One time a young lady (can't quite call her a girl) spent more than twenty minutes coming on to me. I was completely oblivious of this until she sat on my lap and tried to suck my teeth out. That is when I figured it out (I may be incredibly naive, but I'm not totally naive). We had a terrific night together.
Don't try to be someone you are not, and don'tgive up.
May I ask how old you were when this happened? Did this lead to a relationship, or was it just a hookup?
When I was in college, I had a friend that occasionally attempted to flirt with me, but not consistently. We were watching Beverly Hillbillies. There is a scene in which Leah Thompson said "happiness is hard to find", but the joke was that her accent made her sound like she said "a penis is hard to find". My friend looked at and said "it's true; a penis is hard to find." Some time later, she asked me to shoot photos of her in lingerie. This was immediately after she felt rejected by some guy she had been obsessing over. She exhibited signs that signs that she probably had BPD.
Some years later, my roommates had a French friend would visited often. She often talked about people she was dating or sleeping with, and at point I could hear having sex very loudly in the bathroom. At a birthday party, she asked if I like drinking. I said know, then she said "I bet you get a lot of sex. Soon after, she asked me to help make her ex-girlfriend jealous. I don't know why I didn't go for it; something about the whole ordeal felt out of my comfort zone. I just wasn't used to women making direct advances on me and felt confused.
A few years after that, a young lady in bar persistently tried to talk me into letting her wear my shirt. But she just wasn't my type.
My ex-girlfriend pursued me and made it blatantly obvious she was interested. I was attracted to her, but she was the only woman expressing interest in (at least that I could tell). Turns out that she was an emotionally abusive predator who targeted me specifically because my autism made me vulnerable to her manipulation. She abused me psychologically for over two years before she broke things off.
Thing is that if anyone was interested but not so obvious, I'd have no clue. When I started college, I struggled to tell whether women were interested or being friendly, and after a while I started to err on the side that they aren't interested in me romantically or sexually.
I remember one young lady I knew college. We started chatting and got along well, but with no romantic intention because she had a boyfriend. Eventually, she and her boyfriend broke up. At one point, she was complaining to me about random guys hitting on her at work, and I interrupted that to mean she is not interested in dating at that time. This was soon before I started dating my ex, so we fell out of touch. I still don't if she had any interest in me.
Finally, I met a lady at work some years ago. She occasionally flirted with me, but she was having an affair with another co-worker at the time. After a a year or two, she started expressing sexual interest more directly, but at the same time she was going on and off again with her child's father whom she was financially dependent on; and it was clear she just didn't feel ready. Eventually, I got a new job and we fell out of touch. She was about 13 years younger than me, and I struggled with conflicting feelings about the age difference.
But all that was when I was much younger. I haven't had any woman flirt with me at since I turned 40. The last time anyone did hit on me, it was a gay man in a bar; and even that was over 4 years ago.