This post may come across as harsh: but it's the brutal truth. It's important lessons I've learned.
Frankly, I just don't want thirty or forty (11-21 years from now, respectively) to creep up on me without my having accomplished my goals...
You sound like me from a few years ago.
First tip: The single most important thing I learned: don't worry about getting old and leaving things unfinished. Just live your life to the best of your ability every day. Tomorrow doesn't exist. Get that in your mindset! Tomorrow doesn't exist.
Even better - you will not exist tomorrow. That means: work your butt off today!
Tip 2: I spent a good 1-2 years thinking the same way you are "I want to do a business" "I want to achieve my goals by 30", etc.
Guess what - wishes and hopes are completely and utterly worthless when it comes to running a business. They may help your mind - but they will not make you successful. What will make you successful is getting your butt out in the real world and doing stuff. Even if that means working for other people.
I run a business and work with other people still. Guess what? It means more money in my pocket to reinvest later on.
Tip 3: Learn from your mistakes and forget them. Don't ponder them. Truly successful people will screw up, slightly change their methodology, and try again.
Every person has a different "breaking" point. In some cases: even if their mindset is right - some people just can't run businesses. You will quickly know if you are one of those people.
For me personally I messed up a few times, so I took a few years off and got a regular job to develop my skills some more. Now I'm back at it - and that plan worked out pretty dang well so far.
Tip 4: Whatever industry you want to disrupt - get contacts in it first. Best thing I ever did was start freelancing when I was really young. Got to know some of the top guys in my industry, and I still work with them, in some capacity, to this day. Contacts are everything!
People in the industry may not know my name yet - but they most definitely know their names. I use that to my advantage every day.
Guess what - they don't give a crap I throw around their names - because they do the same thing. Everyone does it who wants to get anywhere.
I 100% guarantee people like Steve Jobs, Bill Gates, Mark Zuckerberg, and Larry Ellison threw around their mentors' and colleagues names while revving up their businesses. It's the single best way to get support.
I feel like I am already a step ahead by deciding that I want to create my own business, wholeheartedly developing it for more than the purpose of revenue
Tip 5: You are in it for the money.
Let me say it again: You are in it for the money.
People who say they start a business to "better the world" are blowing smoke up their their own end. People start businesses because they get an idea and want to profit off it. Even charities (those CEOs are the worst... they can publicly look impeccable while pulling millions per year that were supposed to goto "good causes").
Publicly you can say whatever you want - but in your heart you know you are in it for the money. The sooner you accept this, the better.
Humans are incredibly selfish creatures. It's actually a good thing - since for the most part it causes us to help one another.... to get our reward.
Tip 6: Be happy. If you're not happy - it's time to change something. Even top CEOs sometime leave their companies randomly. They may give excuses - but sometimes they just aren't happy.
Tip 7: Learn how funding works. It can be hugely helpful or it can destroy your business. If you can - use your own money (sounds like you are willing too - which is a huge first step!)
This is especially true when it comes to VC funding... they often expect anywhere from a 2-5x return in less than a year. And they can be brutal about it. I've seen good people run their businesses into the ground by accepting funding too early or unnecessarily - simply because they "thought that is how it was done"
Tip 8: If you have success take it humbly. When people first get cash they will always do stupid things with it. Buying a $100,000 car would be a "safe" thing to do, believe it or not.
It's better than going to casinos everyday and doing cocaine... I've also seen that happen a few times... to some incredibly good people who you wouldn't expect it from.
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One more thing:
People look at companies like facebook, microsoft, and apple - and think they can mimic it. What they don't understand is those companies started with a product, they developed it, and released it (to make money). "changing the world" may have been a dream, but in reality wasn't the business plan.
Even if you come up with some product and don't understand how to monetize it just yet (social networks often have that issue) - it will still be about money.