Both have no reason to be doing what they do. They are both human. Neither shoots fire out their hands, neither can change into animals, neither is part machine, neither can move objects or sense things. They are presented as two normal people. Outside of costume they can walk into a Subway and get a sandwich and never get looked at twice. So why do they do what they do? Why does Robin run around in green tights risking his life fighting bad guys when he could be sitting at home playing X-box? Why does Red X run around in a cape risking his life stealing when he could be sitting at home watching Ocean's Eleven?

The thrill.

Both are adrenaline junkies. Red X's addiction is far more obvious than Robin's in that he doesn't bother to mask it with righteousness. He clearly states he does what he does for himself. He never comes out and says the thrill, but it is possible to glean that from his words. Robin's love for thrills is more apparent in his actions rather than his words. He leaps across buildings despite the fact that he will not survive a fight. Three of the other four Titans can fly, the fourth has been shown to be strong enough to sustain the damage given by a steep drop without batting an eyelash. Robin does not have these buffers. Robin has a grapnel launcher.

Robin has his skills, intelligence, and a long metal staff between he and numerous villains out for his blood. Despite his need for justice and righting the wrongs of the world, he wouldn't be Robin if he wasn't an adrenaline junkie. He would be a firefighter or a police officer. Dramatic and perilous as these professions are in our world, in Robin's fictional land, they do not reach the same levels his job as a vigilante does.

Therefore, Robin and Red X have these things in common: martial arts and acrobatic skills, intelligence, and the need for thrills. What differences do they have?

To start with, Robin has morals and isn't a brat. He may be partly in it for the thrill, but his overriding concern is helping those that need help. He risks his life for others without thinking twice, almost as if it were on reflex. Robin is selfless. He also has a firm moral ground to stand on, though sometimes this ground can be a bit too high for the liking of those around him.

Red X is selfish. He plainly says it himself and is completely unaffected when Robin venomously retorts. He does what he wants to because it benefits him in someway, either by giving him the adrenaline rush he so wants, or by giving him a chance to show off his skills. Even in helping Robin defeat Chang Red X got both of those things.