Thanks, BFB!
I agree with most of this except I don't think age has anything to do with it, but rather preparation. There are some undergraduate programs that are very good at introducing students to academia (while I was applying I was curious and looked at their undergraduate program requirements and was fairly impressed). However, if you didn't attend one of these schools, I feel like there is less room for error in your application, so you need to do things like get an MA, write a perfect SoP, etc.