In my case probably not always the best, but a very effective source of inspiration/motivation:
Making a statement/proving a point
I considers myself a spiteful person and also not very competitive in most cases... but sometimes, when someone strikes a nerve or some thing happens at the wrong time, I feel a strong need to react in an artistic fashion. For example, someone claiming: "You can't create anything meaningful with a lens like that" or "That's not for beginners" (I still consider myself to be one)... you get the gist. So in some of those instances I need to at least try to prove the opposite.
Here's one example, where I'm mostly having fun though... "Flickr Explore" is a daily collection of images which are featured prominently at the site. So everyone in there gets a lot of additional views, comments I think that it's created by an algorithm though and while it's not completely clear how it works, it often chooses similar images for the top spots - beautiful of course, but still, samey. One example is the famous mountain ridge "tre cime" (three peaks of Lavaredo) which have been seen there time and time again... So I though, I might just try and create such an image myself, perhaps I can trick the algorithm into choosing one of my macro images for the top spot. 😁
Of course it hasn't worked so far and most likely won't ever, but it's still a (hopefully innocuous enough) statement to the flickr team, that some tweaking might still be benefitial.
Here's the image in question (showing three tiny nails instead 😉):

Tre cime... again. by simple.joy, on Flickr
Of course there is an infinite amount of more important messages to tell by photography and every other form of art... So if you have ever created some real 'photographic statement' or 'proven a point by photography', please share it as well (at least if it hasn't been used to denigrate someone) - I'm looking forward to it!