I set my alarm at 2:15am in order to gift all of my neighbors at once...if they post a specific request on my wall then I will gift them that; otherrwise I gift "in demand" parts or cappuccino. I will often visit neighbors and see their parts requests on their walls and in all honesty, I try to make a mental note of it, but I do have a very bad memory and being half asleep when I gift doesn't help either.
One of my neighbors deleted me because I sent cappuccino after a full week of sending the in demand parts; that's okay, that was her choice to do so. All in all, I'm just saying that I don't purposely ignore parts requests written on peoples walls but consider that there are a lot of people who gift all their neighbors at once so unless a note is written on their wall then those requests might go unanswered. I hope that made sense