Originally Posted by Sly

Or, they do so much for so many people that gratitude is common and when somebody they care about forgets to say "thank you" they simply don't care because they know the other person loves them anyway.

How often do you buy gifts for other people? Dinner? Event tickets? Doesn't sound like very often. That's okay, perhaps you are not financially able to do so. But do yourself a favor and get over your neediness, the quality of friends you make will be higher and little things like this will not be such an issue for you.