Imagine this situation: You meet a girl who's cute, charming, and can carry on a conversation like Michael Phelps carried the entire U.S. Olympic swim team. You've hung out with her a few times and gotten to know her, but despite all of her good traits, you're just not feeling it. Like an English major's class schedule, the chemistry just isn't there. Maybe you are still hung up on your ex, maybe you envision yourself with someone different, maybe you see her more as a potential friend than anything else. You want to call things off, but you also don't want to hurt her feelings (after all, she has been so nice to you), so you respond in the best way you know how. You ghost her.
She asks you how you are, what you've been up to, and you text back an hour later with the carefully crafted phrase: "Not much, hbu?" She replies quickly and emphatically with something much more substantial than your pathetic excuse for a conversation igniter. You glance at the notifications, but this time you don't respond.
If I just don't text back, she'll get that I'm not interested, right?
No, sir, that is not how the world works. It's not an exclusively female thing to expect that someone who has expressed interest in you in the past would continue to like you in the present. (Pronouns here are used for simplicity's sake.) She doesn't live in your head; she won't instantly know that you aren't digging it anymore if you don't tell her. Ghosting is a cheap cop-out for communicating your feelings.
As daunting as it may be to tell someone the truth, avoiding it is so much worse. Imagine how she must be feeling when you meet a guy who you feel a spark with: everything is going smoothly and you suspect he feels the same way about you as you feel about him. However, one day he starts acting cold and distant. Did you do something wrong? Did you say something to put him off? You scour your memories, you exercise your brain muscles, you do a little (or, let's be honest, a lot) of crying. He won't tell you what's up so you're left trying to figure it out yourself, and you can't go about your day because the worry is constantly on your mind.
So what is the best course of action?
Well, in case this wasn't obvious already, tell her how you really feel. Sure she may get a little upset, she may accuse you of wasting her time, she may be hurt that you led her on, she may spill even more tears, but at least she can get some closure. In fact, both of you can. Now that you finally got the burden of your chest, you don't have to deal with coming up with more excuses and more lies for not wanting to be with her. In the long run, she's going to respect that you had the courage to be straightforward. You're going to realize that confessing your feelings really isn't all that bad. You get over it, you move on, and life continues.