How Do You Know if Someone Likes You So Early?

Knowing that this person really likes you is huge in romantic relationships as well as just regular friendships and affiliations. You want to feel like this person couldn't replace you or at least not very easily so if somebody already likes you this early you're feeling like really appreciate it. Those are all things that you can't find out from a picture or usually a 10 second conversation for those then once they get to know someone so let's say your husband plays World of Warcraft with you every day. It'd be like a funny story to tell about this girl but it would be anything I wouldn't value it as highly as another gamer would obviously right Like where's my girlfriend's super in a crossfit