I am 66 If I make it to Jan 2024 I will be 67.
To be financially stable means you don't need to worry about the next meal and bills and you can afford to lead the lifestyle you want but that has to take a lot of things for that to happen. If there is a certain age that is tagged as a right age, say 30, then it means people who haven't gotten to that age wont have to worry till then, which invariably means, they will have to be financially dependent till then, right? To be financially stable and independent means you have equipped yourself with skills to push your goal of achieving your dream. What should these skills be? Investing your time in getting a college degree, also learn other life skills like problem solving, critical thinking, creative thinking and interpersonal relations as this will help build your marketability status as most organizations look for individuals who can be quite versatile and if it so happens you can achieve these skills at a young age, you are good to go.
Another thing is, everyone has their time for which things can work for them, take Colonel Harland David Sanders, the founder of KFC for instance.