I'm a very shy and socially awkward person especially with people I don't know, because people make me nervous. I usually don't respond when strangers say hi to me, as a matter of fact I run away. I don't intend to be rude, but I automatically get scared. I'm also not a very enthusiastic person, so if I did respond, it's not going to sound like I'm thrilled...and that may also be offensive, but it's just not the way I am.

Don't take it personal, because I promise you it's not. There's no reason for you to stop being yourself...and I may even appreciate your kindness, I'm just not comfortable expressing it.