I loved this clip, and it got me thinking...
I absolutely agree that he's an egotist (esp. 9-12th doctors), absolutely self-absorbed, arrogant, boastful, has an inflated sense of his own importance and of his own power, and of his right to make decisions on behalf of other people.
And yet, to me, it's almost like a coping mechanism rather than a vice. I don't entirely believe that he's arrogant because he can be, but because he has to be.
Nine just came out of the Time War, he's terrified of getting attached to anyone and pushes Rose away ("now forget me, Rose Tyler") because if he gets attached and loses someone again, after his entire planet was destroyed - how does he cope with that? How could he ever let anyone in again? The grief is insurmountable.
So he puts walls up, insults her, makes her feel inadequate ("I did it again, I picked another stupid ape" / R: "I'm not stupid!" D: "could've fooled me!"), and makes her feel like he made a mistake in dragging her along because as soon as he's put in a situation where he might lose her, he can't cope. Maybe if she thought he was a dick, she would leave. Maybe if she couldn't stand him, she would be safe.
But inevitably, he can't help but get attached. Because even in grief, even terrified, he is incapable of not loving humanity and risking everything for us as he has always done. That's not egotism, that's kindness, and when he allows himself to be honest and vulnerable, the arrogance slips away. Then suddenly he's telling Rose that she matters, that she was brilliant, that she was loved. And in that moment he even makes space to allow himself to share that kindness with himself too ("and you know what? So was I").
We see the build up of arrogance so clearly with Ten. With every loss he suffers, he becomes more and more arrogant until he literally cracks and becomes The Time Lord Victorious.
First there's Rose: together they're silly, and giggly, and in love. He's been able to shed some of the trauma from the Time War with the regeneration. If he's arrogant, it's to impress her, and make her laugh, and make light of dangerous situations. In fact, they don't take danger seriously until it's too late.
Then there's Martha: she sees his arrogance from the beginning because he's hurting. Having lost Rose, he's all confident winks, and swashbuckling, and showing off, with the we've been here before so I don't need to explain anything, just go with it mentality and the willingness to put Martha in situations that a kind person wouldn't (ex: Human Nature/FoB).
Even after the events of Last of the Time Lords, he just wants to forget that The Year That Never Was even happened and move on, as if any human could. As if no one was traumatized, as if no one needs help facing what happened to them: literal torture. His arrogance is so off-putting that Martha is one of the only companions to willingly leave him behind, and you see it in his face when she tells him: he knows.
In trying to cope with losing Rose, absolutely self-absorbed in his heartache, he's been impossibly cruel to Martha and she's had enough. Unrequited love, yes. But unrequited love and danger? Unrequited love and being taken for granted and used as a pawn - literally walking across the earth - without so much as a thank you? No.
And then there's Donna: oh Donna. Being a little older than the average companion, Donna pushes back against his arrogance right away (Dr: "she fancied me" Donna: "mad Martha, that one. Blind Martha. Charity Martha." / Dr: "tardis, Time Lord, yeah!" Donna: "Donna, human, no! I don't need your permission").
In the end, she is the reason that he turns to kindness (even as Twelve), not because he's incapable but because she's able to break through his grief and the arrogant walls he's put up to protect himself. She allows him to be vulnerable and honest because she's a safe space to land, not a love interest or a conquest, but a best friend. Once she's gone, he's completely unmoored.
For a while, it seems to hold. Donna, while constantly exasperated by Ten being Ten, can guide him and soothe him and be there for him, and in doing so she accidentally becomes the last barrier to the doctor's arrogance, holding back the floodwaters of his downfall, and the walls are cracking. Because once he's lost everyone, even the woman who loved him unconditionally even though he annoyed the crap out of her, what does he have left? Who is he if no one sees him - truly sees him?
Then his kindness turns sour. Donna's influence, at first, gets bastardized. He saves people, but not to be kind, not to be selfless - actually the opposite. Acting purely from a selfish place, he decides to tell Time to go fuck itself and he breaks Fixed Points in time to save the people who were specifically destined to die because He Gets To Decide, not the universe. Power-drunk and raging and distraught, he saves the tiny humans because he's in control, he's powerful, he is literally God.
The egotist comes out in full force, not because he was destined to be this, not because he believes that he should rewrite the stars, but because he is so terribly, desperately, pitifully alone, and he's scared.
If only he hadn't gotten attached, if only he'd been distant and cold and unfeeling, would he have spared himself this pain? Would he have spared these people their lives? Just like after the Time War, he has nothing left to turn to but the festering nest of arrogance and self-importance that he's built deep within his hearts to keep his conscience safe from yet another wave of unimaginable grief.
