This question is only asked by those who cannot measure how far they have come.

We all have our subjective distances. But if you are a human being, some combinations of the following will be that distance:

1. Sustenance (food, water, housing, money)

2. Community (belonging, love)

3, Self-expression

4. Self-transcendence (altruism)

This is a gross simplification of Maslow, but give me some slack. If you question every person saying "you won't get very far in life" with "how do you measure getting very far", you are not only annoying the other person, but also yourself. Spend that time trying to measure how far you have come.