5. The capital
You cannot start a business from nothing. You need the capital to fuel it up. It does not have to come from your own wallet. That is what you need to think about.
If you have enough money to put into your business, that is great. You are good to go. But are you willing to risk it all in case of bankruptcy?
In the other hand, if you decide to collect the capital from others, you have to share the ownership of your business. This could be a good thing or a bad thing.
That is why you cannot just take random people in as your business partner. You have to choose the ones who can contribute as much as you do. Or at least, you should share the same vision.