Dreaming of a koala is your needs to be close to a nurturing environment. This may be for your own safety or a sense of security where you will be able to function at your most optimal state. If you have recently been stressed out at work, then you feel the environment is not the best where you can learn and further your career.
Your own need to be taken care of like the koala in the dream may be an awakening of finding out that you have a natural tendency to depend on others too much.