Newt Gingrich always reminded me of Bill Clinton -- narcissistic, arrogant, and self-centered. (This seems to be a definitive feature of "boomers," especially boomer politicians of both parties.)
That's why Bill Clinton was able to thrash him so regularly -- Clinton recognized that they were kindred spirits, and knew exactly how to manipulate Gingrich, including how to steer him into making disastrous mistakes (e.g., medicare reform and the budget showdown).
I don't think Gingrich ever did recognize the similarities between himself and Clinton: his arrogance led him time and again to act as if he could beat Clinton at his own game.