The difference between 'on my mind' and 'in my mind'

Oftentimes, most English users make use of these phrases wrongly or interchangeably because they are less concerned about finding out the dichotomies that exist between them. In fact, it takes only an English user who is interested in perfecting his/her grammar to ask questions on the subject matter. One of the most frequently asked questions is "between 'on my mind' and 'in my mind', which is grammatically correct?" Has this also been your question? If yes, kindly stay calm as we sail together.

In determining the correctness of these phrases, context comes into play. Put differently, "on my mind" and "in my mind" are both correct depending on the context. "On my mind" means something is bothering you. For example, "The plight of the widows is on my mind."

On the other hand, "in my mind" means something resides in your imagination.

Examples:

1. How could you have imagined such a thing in your mind?
2. I have a picture in my mind of a perfect world.

If that's the case, does it mean Mark Zuckerberg wants to know what's bothering Facebook users by asking "What is on your mind" on their walls? Well, going by the explanation above, I think it is high time Mark Zuckerberg changed the question to "What's on/in your mind" because Facebook users post what bother them and what reside in their imagination.