A guy once told me if I ever thought I could be a professional artist, I must be having delusions of grandeur.
(yeah, that aged like milk, I was doing pro work only a few years after that)
Oh, and another guy once said something like
"You know, I've always thought you're somebody who's trying really hard to make something deep and meaningful with difficult themes, but with all the skill and understanding of a children's writer."
Oh and this one guy who I told about my comic idea about magical knights who live in a modern sort of world, and he laughed patronisingly and said:
"Ohhh, honestly I'm really done with all these modern fantasy things, it's so overdone. I think you should make something with... steampowered airships. That would actually be original."
(ah yes.... steampunk... that's original!)
....Honestly in retrospect nearly every time somebody has said some crap like this to me, it's been a man who thought he was really clever and fancied himself a great writer. Not one of them has ever managed to go pro themselves or make any works of particular note because they all care too much about showing off how clever they are in their writing instead of using that cleverness to entertain the audience. 
Actual critics tend to have been a lot more balanced and respectful. It's bitter and jealous writer dudes who think they're underappreciated geniuses and that a silly little girl like me who makes weeby comics ought to be in awe of them who I've found to be the most unpleasant. There's a difference between criticising somebody because you want to help them improve, and criticising them because you feel angry that they're doing well or having fun, or to feel powerful.
