You are already 100x more self-aware than I was at 18 so you are off to a good start. I would encourage you to gain operating experience alongside investing. It will make you a better investor. https://hackernoon.com/don-t-even-think-about-becoming-a-vc-7a0f2c29e270. :)
I do like your application of “need” to other aspects of life and your dream is one I share.
Need is easy to define once your company has launched if you truly want to know. Depth of need is harder. And its even harder to define need, pre-launch especially outside of early adopters. Sounds like you are already ahead of the game in the way you are thinking about your biz.
Frontier technologies can take much longer to reward investors but as you can see from the list in my article, many companies who “need to exist” have rewarded all of their supporters in reasonable time frames. Ag is just outside of the expertise of most traditional venture capitalists so raising capital is more challenging.
Lots of good info here. The healthcare dark horse is amazon to offer a vertically integrated pharma, provider, payer solution. Others like United healthcare and optum will try but i bet Bezos has his sights set…..