Being younger than the others can be a problem, from bullying (I never was badly bullied, but still a bit) to some emotional maturity problems. To make the things worse, I was even 2 years younger, not just one... that does lead to some little problems when you're 10-11 and still emotionally a child and are with schoolmates who are 12-13 and entering puberty. But overall, I don't regret it.