When you stop showing effort to a girl, that’s when she’ll start to think that you’re not choosing her anymore, that’s when she’ll be convinced that your heart’s not in it anymore, and that’s when she’ll believe that you aren’t falling in love with her every day anymore because effort is everything to a girl. Whether you’ve been with her for 3 months or 3 years, effort is something that she’s always going to expect to see because it’s the kind of reassurance she needs for her to continue making an effort of her own because she can’t be only one trying, she can’t be the only one wanting to make it work, and she can’t be the only one giving it her all. As a man, you should always be chasing her and making her feel like she’s everything to you and no, that doesn’t mean you always have to make some grand gesture to show her that you care, but it’s the little things that win her over. Without effort, it just makes her feel like you’re bored with her, she’s no longer making you happy, and she’s just not good enough for you and a girl can only feel that way for so long until she feels like you’re not worth the effort anymore. Maybe it’s because she would make such an effort to be with you and she would like to believe that you’d do the same for her, but if you really did care about her, making an effort should be something that’s natural and it shouldn’t be difficult so if it is, then don’t be surprised if that’s how you’re going to lose her and once you do, it would take even more of an effort to get her back.