No one’s. Just because you may lose the ability to want to do things on your own or remember how it once felt to do it by yourself, doesn’t mean that person is incapable of doing it again. However if this person begins to just get into relationships to feel their new found normality of doing things as a “we” is when things get complicated.
I don’t claim to be a relationship expert but I’ve seen too many people fall victim to the illusion that they have regained their ability to be independent again. It’s not that you can’t be single because you can’t be–but more for you can’t be single because you don’t want to be. Sometimes these people don’t see this and they deny that this is what their behavior is like, problem is, the only people that can get them back into their old routine of being just themselves, is lost on so many people moving into different relationships because it has grown comfortable for them. At which, the cure, is unknown.