"What one day wasn't, it can't be" do you girls agree?

Me & this guy were pretty serious but ended up breaking it off cause of some small mistakes that we both made. But we weren't dating. We were getting to know each other & talked & we were actually serious. We always did things that couples do.

But then I made a small mistake which was not giving him enough attention & that was my mistake. & then he told me that he pushed his feelings side & doesn't feel anything anymore cause of that.

We're long distance. We're one country away but in December I'll be going to live there for good with his brother & sister in law.

Help please. Opinions.