What the heck is your goal?
I started working at this fancy Japanese-style restaurant with my motive being the ability to wear kimono.
Our goal is to make you all have fun while studying Japanese together.
When your eye is on the target you know your purpose. You also have your eye on the goal (that's the target, after all!).
The reading is a reading for 目 that's abnormal. You've seen this reading with 目標 and 目次, though, so hopefully it won't be too hard at this point. Just imagine telling someone your 目的, only to have them laugh in your face and begin mocking もく you for it. Now you're not so sure if your goal is going to work.