That's true, but I think the year with Rollo might have affected him somehow (it's another crack theory, mind you). Lelouch retrieved his memories, but that doesn't mean the missing year never existed. For a whole year, he was Rollo's brother - he dined, studied, slept under the same roof as him - he probably even had memories of their childhood together. His relationship with Rollo might have become a habit because Lelouch does relate to people who are close to him. It must be a confusing experience, to know a whole part of your life has never existed in the first place, and to remember the "real" facts to prove that. Even if Lelouch is discarding the whole deal at this point for practical reasons, I think the missing year will be something he will have to deal with later, and Rollo is part of that.
Also, there is a difference between Nunnally and Rollo, which makes Lelouch treat them differently and develop different feelings toward them, locket notwithstanding. Rollo is not blind and crippled. Rollo was not psychologically damaged by his mother's death. he is very protective and doting when it comes to Rollo, but not obsessively so. Lelouch would never allow Nunnally near the Babel Tower because he treats her like a defenseless child a(his child, actually) and his raison d'etre. He wouldn't even let her be part of his scheme to fool Villetta. Rollo actively tries to keep him out of trouble as well and Lelouch accepts that as a given. His interaction with Rollo was more similar to the sort of interaction one would expect from siblings. The problem is: it was not real. I wonder how Lelouch - once he starts talking to the real Rollo - will deal with this and if the authors will have time to play with that at all. In fact, most effects of the missing year in Lelouch's characterization have not been explored so far. Again, I hope they will be addressed at least in the sound episodes.
Re: Lelouch and Rollo - Family bonds
Also, there is a difference between Nunnally and Rollo, which makes Lelouch treat them differently and develop different feelings toward them, locket notwithstanding. Rollo is not blind and crippled. Rollo was not psychologically damaged by his mother's death. he is very protective and doting when it comes to Rollo, but not obsessively so. Lelouch would never allow Nunnally near the Babel Tower because he treats her like a defenseless child a(his child, actually) and his raison d'etre. He wouldn't even let her be part of his scheme to fool Villetta. Rollo actively tries to keep him out of trouble as well and Lelouch accepts that as a given. His interaction with Rollo was more similar to the sort of interaction one would expect from siblings. The problem is: it was not real. I wonder how Lelouch - once he starts talking to the real Rollo - will deal with this and if the authors will have time to play with that at all. In fact, most effects of the missing year in Lelouch's characterization have not been explored so far. Again, I hope they will be addressed at least in the sound episodes.