The brain holds many memories, even after death. You eat the material component and gain the ability to recall some of the creature’s memories–personal history, layout of the creature’s home, important plans, passwords, magic item command words, and similar facts. You must know what you are searching for in the creature’s memories in order to gain this knowledge. Applied knowledge–skills, abilities, and spells–can be recalled, however, knowing how to do these may not grant you the ability to actually accomplish them. After the duration expires, this applied knowledge is lost and you no longer have the ability to recall new memories.