i think this is a common lead-in for depression. It is such a defining point, but it is also very personal and very few will truly understand.
Those that have been there will understand.
As they say, we all die alone. the thing is, regardless of other people's activity, none of us have to live aiming to be alone. We can all act for others if we choose.
Oh yes, even though my inner self feels separated since childhood, it was the main catalyst for me starting the charity to act for others. Agreed that is indeed a choice.