My father used to play with my brother and me in the yard. Mother would come out and say, 'You're tearing up the grass'; 'We're not raising grass,' Dad would reply. 'We're raising boys.'
There's always going to be someone out there... who doesn't believe in you or who thinks your head is too big or you're not smart enough. But those are the people you need to ignore, and those are the times you need to just keep doing what you love doing.