The Doctor loses his memory in the completely unnecessary frame story for Doctor Who: The Ultimate Guide, two hours of clips and talking heads but some directly relevant so that’s okay, so we get a few more in-character moments with Eleven and Clara before it all kicks off.
The quote comes from the Doctor’s assessment of himself after recovering his memory - echoing Seven’s “the more I know me, the less I like me...” here referred back to as we look at his Doctor’s sly streak. Clara assures him he does so much more good, and that she admires how he always wants to help.
Several of the speakers agree with Donna’s assessment that the Doctor needs someone to stop him, as well as someone to encourage him - and of course someone to show off to.
Hunters Of The Burning Stone suggests this goes all the way back to Ian and Barbara, stopping him using that rock, encouraging him to find a better way. His love for humanity comes from our capacity to do the right thing. Placed behind the cut as I read it in DWM and Ian and Barbara were a real surprise there - which the collected comic reveals on the cover, but never mind. It makes what could fairly be regarded as just a case of Early Episode Weirdness fit pretty well.
Because now, well, he stumbles, but on the whole, he always wants to help. “Wouldn’t anyone?” he asks.
That got a bit deep for a couple minutes at the end of a clip show. Well. There it is.
The Doctor believes in good and fights evil. Though often caught up in violent situations, he is a man of peace. He is never cruel or cowardly. In fact, to put it simply, the Doctor is a hero.