Most people don't have the temperament for FIRE. You have to live below your means, save a double digit percentage consistently, and invest.

And you have to do it for decades. You need to be able to tough it out through the worst of times (like the dot-com bubble, financial crisis, covid, and random political chaos like tariffs.)

You have to tune out the noise and always remember that on a long enough timeline, the market only goes up. And if you think it's "different" this time, it won't be for long.

And all of that is made easier by having more income.