For a young person with a high paying job, 50% may be a reasonable portion of your income to save. Mandatory expenses will increase if you grow a family, possib

For a young person with a high paying job, 50% may be a reasonable portion of your income to save. Mandatory expenses will increase if you grow a family, possibly faster than your income growth. And consider putting that money to good use -- improving the world, or rewarding people who are doing good work but not well compensated for it, or creating opportunities for other not-yet-wealthy people to have a chance at a good shot in life.