Why do I feel like a spoilt brat when I receive stuff?

does anybody get that feeling or is it just me? every time when I receive stuff I feel like spoiled brat. I'm not a spoiled brat and I barely receive stuff I want every 7 months. A good example is when my mom bought me Call of Duty: Black ops at Walmart last week. I've been asking for the game since January and again in March which was my birthday month. I didn't get anything for my birthday and no one celebrated it. My mom told me which game I always wanted randomly and I showed her the game I wanted. She told me "since we didn't celebrated your birthday and didn't give you a present I'm going to buy it for your late birthday present" I felt so happy I thank her , Gave her a hug, and told her "god bless you". After we left from Walmart and went to go eat, I felt like a spoiled dirty pig that was feed. Is this normal for me? Like I said I barely receive stuff and I'm not a spoiled brat. I only have a PS3, a bedroom, an ipod classic and thats it