Disappear & some time later reappear

Dear man :) I have one question. Sometimes i write first. Because man on photo like to me. I'm read his profile & information in profile like to me too. It's normal. Some men not answer me. Or answer: "Sorry, i'm already found my women, Good luck" :) O'key. It's normal too. We choose, us choose, very often sympathy are not the same:))) But after, some of this men began regularly check my profile. Sometimes months. Every day :)After disappear & some time later reappear. And again began regularly check my profile. :)) Excuse me, but somebody can explain what's happen? What is it, guys?:) P.S. it's just a woman's curiosity