Is my 3 1/2 year old normal to give up something he really loves?

We have a 3 1/2 year old boy who is pretty advanced in his learning, but not in his social skills. We have had something happen 3 times now that I think it pretty unusual. He begins to cry uncontrollable saying he wants to give his cloths away. These cloths are "old timey" diapers with his name embrodiered on them. They began as burp clothes and turned into his sleeping blanket equivalent. He has loved them and can't sleep without them. The first time it happened he said he wanted Jack (his older bro.) to have them. Then it happened with me the other day. He said he wanted them to stay in my bed. My husband said it happened once with him, but I did not see that incident. He collects 3 or so of these clothes (all that he can find) and begins crying uncontrollably and tries to give them to me. Is this a self esteem problem? Any insight?