Many have some degree of personality differentiation, even if the space of possible variance is pretty narrow compared to humans.

Me, internally: No way that's true. But, well, just in case...

(five minutes of googling)

I'm learning all sorts of new stuff today!

To the extent I'm interested in justifying that, it's that I can make a difference here and now for this organism, and want to do so.

That sounds like a perfectly valid reason to me.