What are falling in love dreams about?

So today I had a dream where I fell in love with a girl who lives on my street who I've never even talked to, now I won't get into details of the dream but when I woke I was feeling so depressed knowing I'll never have her

Hi, last night i had a dream, where i met nicest girl,it wasn't sex dream - we talked,we laughed and kissed, but in the morning, when I realized that it was just a dream I became depressed for the whole day,and all day I only think about that dream and I know that it was just a dream, it is a very strange feeling - fall in love in the dream.Has anyone felt the same way? I've been alone more than a year,I guess I miss another person's touch.(Sorry for my bad English,not my first language)

It was as if I had seen the real world, not the one that we are in but, a dystopian place where people who consciously dream are locked away for fear of finding the real world. I escaped from the prison to eat my favourite food, chicken schnitzel, due to the fact that in the prison you barely got to eat and a lady (That I knew was guarding the real world trying to catch dreamers) spoke to me and asked me if I was ok, I stared blankly at her, she replied with "Oh good I almost thought you were conscious" with a sinister smile. I heard speak of someone once I had left the restaurant talk about words that would unlock the gates to the prison and let the conscious dreamers be free, I found other dreamers, fell in love and walked amongst the rooftops of cities and through streets for what felt like days. I found myself reaching a pinnacle of a grand tower, that stood above the city and the code words that would set the dreamers free, I returned to the prison, near the restaurant that I had broken into, the same lady spoke to me she was angry with what I had done, that I would let people know of the real world and with the words of power, I let out all the people into the real world and woke up.

I feel so angry and stupid because I'm in love with someone who most probably doesn't even exist or even if he does, I won't ever cross paths with him. I feel so helpless because I really really want to be with this guy and he's not even real. It's frustrating and hurtful and i feel really stupid. I know that I shouldn't give this much thought and it tends to happen and that I'm getting sad over nothing but it's just that I really really like this guy and he's the only person I wanna be with. I'll never meet anyone like him and idek if I'll like anyone who's not him. Sigh this sounds so childish but I really wanted to let it out :(

So I'm basically depressed right now because last night I had a dream about the most beautiful girl I've ever seen, (never seen her in real life though) and we basically ended up falling in love. In the dream for some reason I forgot to go to her birthday and wrote a letter to her and that's when it ended. I woke up and realized what happened in the dream and literally almost cried. Has anyone else had this happen to them? If so, is it some sort of sign?