I've had a few throughout my career:
You should really focus on C, don't bother learning Python.
Focus on whatever makes you happy. You'll be way more likely to succeed.
There are definitely times where it makes sense to slow down, especially if you're burning out. But momentum can be extremely useful throughout your career.
You shouldn't try to go to university, you don't have the attention span for it
This was my grade 11 music teacher. If I had listened I wouldn't have gone into Computer Science. Don't listen to people who try to limit what you can accomplish.