If you’ve got a great idea for a future venture, here’s some humble advice: Don’t listen to people who claim to have seen everything.
First, I seriously doubt they have “seen everything.” And, if they really have seen everything, there is one thing they can’t have seen—and that’s what has not yet been created! (Remember: Often, one person’s “25 years of experience” is more like “One year of experience repeated 25 times.)
A second piece of advice: The more original your idea, the fewer people there will be who can provide useful input. In other words, the originality of your idea will be inversely correlated to the number of people who “get it” and can offer constructive criticism.
My final piece of advice: Listen to yourself and create your own future.