memoirs vs. personal essay

Altough I was absent from class on Wed the 31st, I was doing some thinking on the differences between memoirs and personal essay. I think the 2 differ in a few ways. I feel memoirs display more of an actual account and reenactment of a situation, while a personal essay can be such a thing, but also must have more of an opinionated point of view. Some dictionaries define memoirs strictly as an "aoutobiography", which i guess is a pretty accurate definition. A personal essay, though, I think is vital to understanding the thought process an individual may have, because its more opinionated and more "peronal" so one can become more involved into what the person is thinking.