How do you know if you actually like someone?

I guess this is a question for demiromantic people.

I've always considered myself aromantic, I've never felt romantic attraction, never wanted to date a specific person, etc. But now, I'm having doubts... Sometimes I feel like I might actually be feeling something for someone I'm talking to. But since I'm very inexperienced, I can't tell if it's real or just my brain fantasizing, lol.

How did you know you wanted to date a specific person?