Special means "better than ordinary." Like the self-portrait you lovingly painted as a surprise for your sweetie's birthday, something special is distinct, and surpasses the norm.
Something special is looked upon with affection, surpasses expectations, or has a particular role. It can also be a featured attraction or limited-run occurrence — like when there's a special on television or a special on cheese at the store. Ray Charles said, “Love is a special word, and I use it only when I mean it. You say the word too much and it becomes cheap.” Take this sweet crooner’s advice and don’t wear out special sentiments.