You could also be getting older a little, I know my imagination was all I had when I was a preteen, I was always in fantasy land, my teen years were all about fantasy, and emotions... lots and lots and lots of emotions. Now as I am almost 30, its fantasy, emotions emotions emotions and precision/logic. The new thing my mind is doing is that its becoming incredibly logic based, it rips things apart and organizes it into a system, I can put this to use on any "fantasy" or abstract based thoughts and feelings generally. Concrete example is how I organize friendship inside my mind, it used to be about emotions, now its so much more its a huge abstract concept thats seen from differnt angles and perspectives, when I put it into this like little model inside my head its almost like a game, I start finding ways to make moves in advance, like getting better at chess. Instead of losing all your pawns you start organizing them into strategies but only because you can see them all working in tandem with the rest of the pieces and in opposition to your opponents pieces while you are trying to figure out emotionally "what kind of move would he make next because what kind of person is he?"
I dunno its hard to describe...
My belated point is that, they say it takes 10ish years to conquer your cognitive preference. If this is true, then it would explain how I could be so emotionally distant and cool as a child with only flashes of great sensitivity/feelings but always stuck in la la land because I was basically just my Ni preference and my other preferences were still way long to be developed. By the time I was 11 or 12 I became very moody, I started noticing girls, wanting to be normal, wanting to blend into everyone else and not be noticed, just really emotional. If this was the dawning of my figuring out how to use my Fe then that makes sense too, because from around 12 to 26 or so thats who and what I was. I will always prefer to be my Ni over all because its just what has been what I have been for as long as I can remember. But this logic stuff, its still new and I am learning how to do it every day. I listen to logical people I become drawn to them I want to see how they do what they do, this is like a conscious/subconscious thing going on I can tell... But its the counterweight to my paranoid and emotionally fragile core that has developed here to now.
And I am glad, because goddamn I needed it. At the root of it all the logic will never replace how I value and what I value, it will simply offer me new ways to consider things and new data and new insights into concepts affecting me. At the root, essentially I think what the logic development is just my mind giving itself new choices.
Instead of being a slave to my heart and not being able to see whats wrong for me because I am in love with it I can see the naked and practical truth, and it offers me choice, I can stay but I will be aware of my irrationality or I can be rational.
So maybe you arent getting dumber, maybe you just dont need to engage your imagination quite as much or you are moving on to figuring out some new preference.
