“One day you’ll discover that the opinions of worthless people are worthless.”
Piers Anthony, A Spell for Chameleon

Don’t listen to those who have never done something.

People that say you can’t do something are usually telling you what THEY can’t do.   They don’t have your motivations, skills, and burning need to accomplish that drives the top quartile performers forward.

Someone sitting at their desk, watching the clock until retirement in 27 years has zero relevant vision, skills, or internal drive to tell you what you can’t do.  Ignore them as you put your head down and build something incredible.