Every drop out I know regrets it. Can you be successful without a High School education? Yes. Is it usually much harder? Yes.
It's not harder at all. High school is a joke and a waste of time. You can forge your diploma and no one will even verify it, because it's such a joke. But why would you even want a diploma? I've never needed it and I don't even have one. The world is vast, full of opportunity, why on Earth would you want to be an employee?
Age is no matter, children as young as 15 are starting businesses and making money. Middle school and high school are the only reasons some of you might think "a 15 year old can't start a business". Yeah people who think that have been made to feel small from that 'education' *cough* brainwashing *cough* they received since puberty.
High school is a holding pen for young creative minds where they are beaten down mentally into accepting their lowly hierarchical position. You are made to submit to authority and group think is encouraged. It makes slaves out of any who don't think to question it.
As for the people who are there to learn 'marketing and entrepreneurship'. Another joke, you're learning from dinosaurs, you're wasting time on exercises that don't matter. Go start a real business, fail, and learn. If you're lucky you'll become a millionaire. It's not hard to do that either, again high school brainwashing has taught you that money is hard to get. That you should work for years, years, and years to be a millionaire.
All you need is to apply your intelligence and solve a problem better than someone else. Don't read a marketing book your teacher tells you to and then write a paper on it. Read 10 marketing books from the greats and then go start a business with a loan from a relative. This is entrepreneurial, not listening to a teacher who has most likely never applied the things they teach, in a classroom with twenty other people who will use their 'skills' to market smart water.
Apologies for the long rant but as a grade 9 dropout I wanted to chime in.