That is one reason that finding an investor seemed so important to me on my first company. I thought I needed their validation, even more than their money.
Validation from a VC is the worst place to get that though! I didn't learn that until my second company. It is far far better to get validation of your idea from preorders or even better, from paying customers.
I guess that is why I love The Lean Startup by Eric Reis so much. It gives you permission to make an MVP and get going fast, get validation of all your assumptions from real customers!
However, The Lean Startup fails a bit too. It doesn't tell you what it will be like, that you will hit bumps, and that you must persist (more than just pivot) but persist-pivot! It also fails to tell you how to actually build that MVP and get it going!
That's part of Europe I wrote my book: Lean Startings. Through storytelling, you learn what it means to persist, to fail, and to succeed. You also learn how to build that website, how to take preorders or orders, and ultimately how to fulfill and satisfy customers!
Please get my book; I wrote it for you!