I think people will ALWAYS have an opinion about something and at the end of the day, marriage is never guaranteed no matter what age you are. It takes work, and love and any age is capable of both. I've been with my FI for 9 1/2 years since we were 16. I didn't know then I was going to marry him but by 19, I knew someday I definetly would. We will both be 26 when we get married. Live YOUR life, have fun, and as long as you feel he is THE ONE, I say go for it and congrats!