Lincoln was a lot more observant than people gave him credit for. His parents thought he was withdrawn and just didn't like social situations. Nina thought he was shy. Usnavi and Benny just accepted it as one of Lincoln's funny quirks, that he talked less than everyone else.
What he was really doing was watching others, getting a feel for what they liked to talk about. He noticed habits that they had, like looking down at the floor periodically or clasping their hands together in their lap. He could tell when they were embarrassed, when they were excited, when they were flirting – even when they themselves had no idea.
Lincoln watched everyone with the same devotion, but his eye always seemed to be drawn back to Benny. He would watch as Benny's eyes flit around the room, which was a sure sign he was about to tell a lie. Whenever he was teased, Benny would bite his lip before retorting. He would do the same whenever a teacher caught him off guard at school and asked him to answer a question. Lincoln came to realize that Benny chewed on his lip when he was thinking of what to say next.
His favorite of Benny's habits came when he was flirting. He had a habit of turning his head slightly to one side and touching his chin to his shirt collar, which Lincoln felt was just too adorable for words. Any time Benny would do it, Lincoln would find himself blushing, even though Benny's attention was anywhere but on him.
It was not a very good day for Lincoln when Benny finally got a girlfriend, for that meant he had to watch the two of them look at each other all during lunch. It was a blessing, then, that Usnavi normally left his homework to the last possible minute, meaning he did quite a bit of it at lunch. Lincoln would turn his back to Benny and focused completely on Usnavi, pointing out misspelled words or wrong answers on math problems.
"Link, seriously, are you gonna be a teacher or what?" Usnavi asked him one day, scratching out another wrong answer with a dulled pencil tip, as he had chewed the eraser off. (Lincoln had noticed that whenever they had a pop quiz, Usnavi started chewing on his erasers, a sure sign that he had not read the assigned pages the night before.)
"Maybe," Lincoln said, pulling Usnavi's paper towards himself and going over it with his own eraser. "There you go." Usnavi gave him a grateful smile before saying, "Thanks, man. Sometimes I just don't have enough time to get all this done at home, what with working at the bodega and everything."
((Idiosyncrasy))