Yes there is a difference. Lying requires a motive to tell someone the wrong things. Changing your mind is just because you have a different mindset. As long as you inform the people of this change and, when neccessary, what prompted it, you should be golden. read more
There is big difference as long as you haven't pre meditated your answer to eventually change it . A lie is something you know when providing incorrect information while answering a question . Changing your mind after an answer is completely OK and normal and they stand in two different area's far apart from one another. read more
Change of mind is not an intent to mislead/misinform. And I think that generally, people consider "promises" to be "within the best of my abilities, I will do this". Unforseen circumstances out of your own control really don't constitute a lie. read more