I'm sure it does, but one person isn't going to suddenly make you rank first page. It's a collective thing too, so I mean, if you started a year ago and watch every video to full 100% that is 365 views and 100% on those views (lets say you did a video a day).
However, what about the other views you get? What if your normal retention is 20% and you get 9,035 views in a year (that number makes easy math for me).
Total Views at 20% = 9,035
Total Views at 100% = 365
90% of your viewers only watch 20% at that point, does that make sense?
Basically what I'm saying is your one view isn't going to sway an average enough to get you ranked. That being said, I have two accounts and always like and watch my own videos 100% through, but that is more of a QA thing where I make sure it played back well when its scheduled, then when its live I check on my other account and make sure annotations and stuff all worked.