Guy here. I've missed many, MANY signs. Here's a few:
One girl in high school had a blog. She was writing about me on a fairly consistent basis. I had no idea until I saw her and one of our seniors walking home a block ahead of me. He turned back, saw me, and proceeded to tie his shoe until I got there.
One of my ex's kept hanging out around my locker. She would say hi, poke me with her finger. Eventually she just asked one of my friends for my e-mail.
I was out at a karaoke bar when I got a text from an old friend (whom I hooked up with previously). She invites me over. I get there and she's in bed with another girl and says I should probably stay the night. I was in bed with 2 women on either side and didn't realize it until the next day.
I'm at a club and decidedly not sober. There's this gorgeous woman eyeing me. I sit down. She sits down beside me, puts her arms over my lap and leans to talk to another guy on my left. He leaves, she turns to me and asks: "Do you want to kiss me?" My brain thought: "Yes." Those weren't the same words that came out of my mouth. GG brain.
In one of my university classes there was this cute girl behind me that would always ask me how I did on tests and essays. I was pretty honest, including when I bombed one essay. "You're so smart though. You should e-mail me your essay." I thought she wanted to copy my shit. I didn't realize until after that class was over.
I'm at an EDM festival in line to get water. Chilling out, doing my own thing. The girl in the line next to me keeps looking at me. Eventually she turns to her friend, a guy, and says, "He's listening in on our conversation," while staring at me. They weren't talking before.
Girl made me a mixtape when she found I was going on vacation. Of my favourite genre.
Another girl folded 1000 cranes for me when she found out I was going on an exchange program overseas for a year.
One year, I wasn't going to celebrate my birthday. Lady-friend finds out, arranges a surprise birthday party for me. She always hung out around me whenever we were together. I didn't get the hint.
That's just a few.
Edit: Accidentally a word.