Isn't there a theory that you develop your functions at different rates? For example, my childhood would be very Ni dominated. Adolescence is when I was working on my Fe. Currently, I'm in my Ti stage through adulthood. Later in life, I'm supposed to work more on my Se? I feel like I read that somewhere & I honestly agree with it.
If, theorectically, that is the way the functions develop then I bet my type seemed to shift a bit throughout the years. It's also why if I take an online test, I'll occasionally test INTP - I'm supposingly in the developing my Ti stage.
Who knows if it's true, but I figured I'd throw that out there.