I think it does change Memento... for the worse. The beginning is a powerful, integral part of the movie.

Skipping the first 10 minutes is like skipping the last 10, "I just know where this is going anyway". Nope. So much can happen in 10 minutes! Plus, you know, they filmed that part for a reason.

It's also like skipping the first chapter of a book: sure, some books would be improved by trimming their clumsy beginnings, but good books aren't.