He broke up with me a month ago, he was sort of cold, he responded to me at first then ignored, and didn't seem too bothered. He regretted it after a while, then spent a couple of weeks chasing me, sometimes it got too clingy where he would be begging for me and saying he doesn't want to be without me, misses me, loves me, wants me back, he's sorry. Randomly contacting me etc. I didn't give too much away but eventually gave him a second chance. He asked me to be with him again and we became a couple. Instantly he went cold again, ignored me, didn't seem to care, would be online posting on Facebook literally 30 times a day (unusual for him) and not contacting me. I said it's over and he didn't even contact me over it, he's completely ghosted me after he got what he wanted which was us back together. This hot and cold act is confusing, why do some guys do this?