Can be confused: grateful, gratified (see synonym study at the current entry).
Synonyms 1. obliged, indebted. Grateful, thankful describe an appreciative attitude for what one has received. Grateful indicates a warm or deep appreciation of personal kindness as shown to one: grateful for favors; grateful to one's neighbors for help in time of trouble.Thankful indicates a disposition to express gratitude by giving thanks, as to a benefactor or to a merciful Providence; there is often a sense of deliverance as well as of appreciation: thankful that one's life was spared in an accident; thankful for the comfort of one's general situation.3. pleasant, gratifying, satisfying.
1552, from obsolete adj. grate "agreeable, thankful," from L. gratus "pleasing" (see grace). "A most unusual formation" [Weekley]. Hard to think of another case where English uses -ful to make an adj. from an adj. Grateful Dead, the San Francisco
rock band, took its name, according to Jerry Garcia, from a dictionary entry he saw about the folk tale motif of a wanderer who gives his last penny to pay for a corpse's burial, then is magically aided by the spirit of the dead person. A different version of the concept is found in the Egyptian Book of the Dead.