Some people do manage it, and some particularly shifty sorts manage several times--but it does seem to be incremental.

Coming out of my teenage years with a painfully-acquired stoicism and dedication to freethinking, I've been able to shift myself to pragmatism with a non-dogmatic mystical ironic idealism skulking in the background.

Don't know how far afield I could get before the software compatibility issues cropped up too much. I know I could never boot a personal God without some real serious changes.