Mirror

The perfect psychological instrument, heals any depression, insecurities, mental trauma and shyness, may also induce a complete 180 degree personality flip. This occurs by the character taking 5 minutes to remind her or himself of their successes or the necessecity for them to behave that way.

It is unknown why Mookie has not yet patented this method, since it would easily replace all psychiatrists on the planet.
Note that a physical mirror is not necessarily required; it's the 5 minutes reflection that counts.