If your answer is yes, let's dig a bit deeper.
Admit, these days they wait for you at home; you have a small kid who always admires seeing you after your working day, or perhaps you meet an old friend you could not look up for a long time, or maybe there's an interesting event or chance that you have been waiting for all your conscious life.
Later, when you happened to be alone: maybe kids grew up and left your home, or all your friends appeared from time to time, but there was no one you were pretty happy to see.
So you are alone with inner idleness, feeling kind of emptiness, something distracting, and thrilling at the same time.
For the entire life, you just weren't fulfilled with yourself.
First, you had a thought that kids could improve your state, left a bit of life for them. A bit, exactly? Second, your significant people in your life. Do they still actually stay meaningful?
Or anything else?
You have met yourself. Why do you live for? What is your goal at last? What have you learned, and how will you use it further? What is your place in your mind and among people?
Have you ever been happy, indeed? Try answering these questions, and say it for yourself.
And if the answer is no please, read all the above carefully. Take good care of yourself!