
Ah, I absolutely think it would. We are defined by our education, our experiences, our memories. This and they way we learn(ed) to deal with stuff is what makes us as individuum, what builds and changes our attitude. If you forgot about all this you are practically like a blank sheet of paper. But I also think it depends on the state of memory loss: till when and what. Do you know the film “The Vow” with Channing Tatum and Rachel McAdams? It is loosely based on a true story of a woman who lost her memory after a car accident. She forgot about about her life as an artist, her husband, friends etc. In this case the person was catapulted back to the time where she studied jura, had a different fiancé, different lifestyle etc. AND back to her old attitude. Which wasn’t very likeable …
Two quotes out of this film:
"Life's all about moments of impact and how they change our lives forever. But what if one day, you could no longer remember any of them?"
"The truth is we're sum of all the moments we've experienced with all the people we've ever known and these moments become our history."
It’s a really good romance film btw.

Yes, it would if it is permanent memory loss. If he forgot everything and had to relearn it all (which is very rare but can happen). Here, a link to Mayo Clinic Amnesia page:
http://www.mayoclinic.org/diseases-conditions/amnesia/basics/definition/con-20033182
And a Medical News Article with more info:
http://www.medicalnewstoday.com/articles/9673.php

Stranger in the Family is another good one. It shows a family trying to deal with their 16-yr-olds amnesia from being hit by a drunk driver on prom night. It is based on the real story of Steve Thompson who had to relearn everything from scratch, including walking and talking. He was reduced back to a baby essentially. It is not a love story, but a good story about overcoming it. Here is a link to an article about the kid and family the movie was based on. http://www.deseretnews.com/article/190019/AMNESIA-TURNED-TEENS-FAMILY-INTO-STRANGERS.html
amnesia? would that change your attitude too?
( ̄へ ̄)