For me, one of the worst feelings is regret.
I fear the day I will wake-up and ask myself: "Why haven't you done that?"

The reason can probably be summarized into a single word, "fear."

What Are We So Afraid Of, Exactly?

The fear of disappointing someone
The fear of being alone
The fear of being unemployed

The thing is that we are asking ourselves the wrong questions.

Are those fears have any impact on your life?

Why do you care what others are thinking? Do you live for the others?
Why being alone would be a mistake? You love others more than yourself?
Why being unemployed is a shame? Don't you enjoy all this free time for doing stuff you love?

We should probably stop overthinking and free ourselves.