To me this is a song about an affair during summer, maybe during holiday, which had no intention to last. It wasn't that serious.
The singer hasn`t been honest with his lover during their time together and now, after he had to return home, he regrets this by saying that he would actually need her right now. And that he is hoping that she will remember him and his affection. Meaning that his feelings have grown since they departed.
To me this is a song about an affair during summer, maybe during holiday, which had no intention to last. It wasn't that serious. The singer hasn`t been honest with his lover during their time together and now, after he had to return home, he regrets this by saying that he would actually need her right now. And that he is hoping that she will remember him and his affection. Meaning that his feelings have grown since they departed.