(Code Geass R1 and R2 spoilers)

On foot against the crowd—Lelouch’s immunity to others’ emotions.
(R2 episode 03)

A crowd, if you think about it, is a powerful thing. True, it has little consciousness of its own and therefore is not hard to control, but this also means it is easy to lose oneself in it. If it takes an incredible amount of struggle to preserve a will of your own in even a group of just four people, imagine the difficulty when a personality encounters the complicated and much larger society of a country. In the periods of rallies at the end of WWII, people were out walking the streets in the thousands, without any knowledge of what was going on. Later, in memoirs and interviews, people would describe it as just “a massive feeling”: a sudden impulse to walk out, that each of them interpreted as an act of their own will until they saw their neighbors doing the same thing. 

I think George Orwell described collective unconsciousness’ work the best in his famous novel, 1984:

…the Hate rose to a frenzy. People were leaping up and down in their places and shouting at the tops of their voices in an effort to drown the maddening bleating voice that came from the screen… The horrible thing about the Two Minutes Hate was not that one was obliged to act a part, but, on the contrary, that it was impossible to avoid joining in. Within thirty seconds any pretense was always unnecessary. A hideous ecstasy of fear and vindictiveness, a desire to kill, to torture, to smash faces in with a sledge-hammer, seemed to flow through the whole group of people like an electric current, turning one even against one’s will into a grimacing, screaming lunatic. And yet the rage that one felt was an abstract, undirected emotion which could be switched from one object to another like the flame of a blowlamp…

It is this exact level of emotionhysterical mass behaviourthat doesn’t penetrate Lelouch’s skin. A group is naturally victimized by emotions simply because they replace consciousness, and so it takes an incredible skill of boredom by knowledge to preserve this awareness. 

The whole country is raging and screaming “All hail Britannia”; meanwhile, Lelouch is only slightly involved on the emotional level. He becomes even more skillful later in the series.
(Episode 6, R1)

Part 3: “How should a man live, that despises his own country?”

Now, let’s give a proper answer to the main question of this article, as well: “Why is Lelouch so attracted to such dangerous events?”

Emotional redirection

Throughout his life, Lelouch develops a traitorous nature: an ideology similar to Suzaku’s, who likewise went against his motherland (see “A fake traitor that didn’t commit any treason”). This repulsion to his own kind naturally engenders a disposition towards potentially treasonous actions. However, as any demonstration of his real thoughts and emotions—especially among the high-ranked and pure-blooded Britannians—would result in exile, Lelouch keeps his unpatriotic thoughts to himself.

But holding it all inside is impossible; Lelouch will simply snap at the “best timing ever”, and the Ashfolds will be left with no choice but to apprehend him and Nannally or throw them both out on the streets. Thus, Lelouch finds himself a suitable hobby, where his hatred for Britannia is spent on nameless streets. Here, his name is unknown, and his hate stays unnoticed by the authorities.

But why protect the Japanese, whom he has no relation with?

Those of you with power, fear me! Those who have none, rally behind me!

Lelouch’s hatred was born when his father, the emperor, suppressed his ten-year-old son’s first “rebellion”. Lelouch, a young child, had rushed into the castle seeking help in a desperate situation, fearing the loss of his family. But from his father’s point of view, his cry for help was seen quite differently. 

Lelouch is exiled from the Empire and used as a bargaining tool with Japan. (Episode 7, R1)

After his exile to Japan, Lelouch sees himself in every humiliated Japanese citizen: a helpless ten-year-old boy, unable to fight back against the strong and stand up for himself; a person desperately needing protection, someone with no one on their side. Trapped by an indifferent society, they have no one to turn to. Lelouch instinctively rages against such a world, where there is no place for his sister and himself. This rage, which had been buried deep inside of him during his previous “official life”, is now being fully released in protection of a nation that has fallen victim to the same man’s actions as he has fallen victim to. 

“I will overcome this…” (Episode 7, R1)

To sum it up, we see several important lessons in Lelouch’s “hobby”, in which his real personality is revealed. 

Without any hesitation, Lelouch rushes in on any unjust Britannian, in whom he sees an image of his father and the source of his hatred. But neither the emotions of the panicking Japanese, nor the flaming aggression of the Britannians, affect him; Lelouch understands the true nature of such conflicts, and they do not emotionally hook him. 

The only conflict that Lelouch allows into his heart is a personal one, related to his father’s treason (and his mother’s as well, as we find out later). However, even here in “Ragnarok Connection” (episode 21, R2), these emotions do not stand in the way of his plans as Zero.

Even while wiping tears of sorrow, Lelouch firmly proceeds with the philosophical dialogue with his parents. He beats them with ease in a competition of the world’s brightest minds battling for control. (Episode 21, R2)