When you live alone, like me and all but a few estranged members left in your immediate family and all of the extended family gone elsewhere, long out of touch, you realize that you are alone. You realize when you die, there won't be anyone to remember, anyone to mourn or grieve, or anyone to care.
The world will still go on since no one else knows about you. Everyone will be busy with the lives not even knowing you existed. The whole world will continue as it did when you were alive. It won't skip a beat, give a moment of silence, or give a thought beyond disposing your belongings.
No one will wonder who you were, no one will care what you did, and no one will remember you. Only you, no one else, and you'll be gone. When you live alone.