"As the same thing in us is living and dead, waking and sleeping, young and old. For these things having changed around are those, and conversely those having changed around are these." - Heraclitus
"All life is flux and nothing stays the same". - Plato
Our personality formation normally occurs early in our development, but who we are, things we experience, situations beyond our control change our perception and our thoughts. This is a process that is always working and reworking. I find it odd, could just be me, that people think we do not change and then give a list of ways that we do indeed change. Everyday, you are engaged in life, you adapt, you modify, you conclude and adjust your mode of operatus based on input. Things we can't control, such as sickness, etc change us.
The degree of change is the issue here. The exact change and where and how is the issue here. We may hold a basic belief or philosophy, and while we may learn things, we may still hold that core belief, but to say we do not change, I believe is quite incorrect. Every person here is a result of a change in thinking. Now you still may like ice cream and prefer vanilla over chocolate because that's your core, but you changed and you change every day that input goes in your mind. The degree of which is up to you. It can negative, postive or neutral and just moving forward.
Human nature is about change, so the answer is yes.