Hi! Hope someone can help me. I just got the Kooba Sienna in black...I love the look of it, it's a pretty simple black bag, love the feel of the leather...but my shoulder hurts after 10 minutes of carrying it...please help! I want someone to tell me that this will get better, or after my shoulder gets REALLY numb I won't notice it! I don't want to return it but thats alot of money to stick in the back of the closet after a month. Thanks