When you are feeling at your best, you might want to hang out with a certain group of people. However when you are feeling low, those people might not be your true friends and help you through your tough times. So, stick with the people who are supportive, and ignore those people you wanted to hang out with at first, because they aren't always true friends. Also, what I get from this is that if you only hang out with group B when you are low, you might be taking advantage of them because you are only with them when you need them. Its best to stick with the friends who are supportive and help you, and when you are feeling good yourself, you can help them.