1. A method for adjusting behavior of a device based on the device's experience, said device comprising: (i) a sensing unit for sensing signals; (ii) a concern-generating unit programmed to generate concern-parameters; (iii) an emotion-generating unit programmed to generate emotion-parameters; and (iv) an actuating unit for actuating the device, said method comprising the steps of: (a) recognizing an object based on signals receivable by the device, said device having initial concern parameters; (b) extracting information, if any, on concern-parameters from a memory under at least the index of the object, said memory storing under the index of the object, information on concern-parameters previously generated by the device through past interaction with the object; (c) modifying the initial concern-parameters by the extracted information on concern-parameters; (d) actuating the device based on the modified concern-parameters and emotion-parameters generated by the device based on a discrepancy between the current concern-parameters and the modified concern-parameters under predetermined rules; and (e) inputting in the memory, under the index of the object, concern-parameters generated by the device upon interaction with the object, thereby updating the memory.