Lol. On this instance, were talking about someone who previously led a robust, full life as a single person and didn't have a problem with solitude.

Not someone who can't stand to be by themselves.

Some people enjoy their own company. When they're alone, they're in good company.

Some people can't stand to be alone. They're usually unhappy or dissatisfied with themselves. Some of them self-loathe as much as possible.