One time, James impressed Lily.
He was completely unaware of this, actually. It wasn't done on purpose, and wasn't planned. James wasn't even aware that Lily was present during thus impressive moment. But nonetheless, it had happened, and Lily couldn't ignore it.
Lily was on heading to the library, her bag slung over her shoulder, her arms full of several large books. There was a test in transfiguration quickly approaching, and she needed all the studying she could get. Entering the library, she smiled at a small cluster of students as she passed several younger Gryffindors who were vacating a table next to the one she was dumping her study supplies onto.
She had just left the common room, where she had been trying to study, but found that she could get no work done because it had been far too noisy. So she had retreated to what she had hoped would be a peaceful atmosphere in her dorm only to find that some of her dorm mates were having a row about someones stolen boyfriend or other, and didn't sound like they were finishing anytime soon. The obvious next choice was to flee to the silent confines of the library, where any noise was rewarded with an irate Madam Pince breathing down your neck. Half an hour later, Lily found herself here, immersed in a thick volume of Standard Spells, looking over and trying the memorize the sort of complicated wand movements needed for such and such spell.
Pulling her books closer towards her, Lily squinted at the page, trying to understand what the diagram was telling her. Another few minutes passed before the Head Girl huffed in frustration and reached out to pull a different book closer. Instead, her hand knocked said different book to the ground, where it fell with a muffled "thump!".
Lily froze, hoping against hope that the vulture like librarian hadn't heard the books abuse. A moment passed and Lily let out a breath she hadn't realized she'd been holding and ducked under the table to retrieve the book.
Crouching awkwardly under the table, she reached out a hand and grabbed the book, sliding it closer just as two pairs of feet came down the aisle. The red head sat frozen under the desk, blush creeping up her cheeks at the thought of being found with her limbs and robe and skirt all tangled in a jumble, squatting beneath a table. She was trying to decide how to get out and straighten herself out without losing the dignity that came with the title of Head Girl when the first voice spoke, and she decided she'd rather stay where she was.
"Come on, James. You never do anything fun anymore. Just one prank- that's all I'm asking. One. We haven't had any fun with him for a while." Lily shrank down and tried to make her self smaller as Sirius and James passed by her table and sat themselves down at the table the younger Gryffindors had just left. She tried not to growl out loud in frustration as she listened to James sigh and watched him kick his feet up on an empty chair, making himself comfortable.
"Sirius, aren't we a little old for this? I mean, yeah, Snape's a prat, but he hasn't done anything in a while. We should focus on preparing for McGonnagal's test. She's sounding like it's going to be hard."
Sirius scoffed. "You sound like Moony. 'Be mature, work on school, kiss all the teachers'-'"
"And why is sounding like him a bad thing? Maybe he's right. We've had six years of messing with ol' Snape. This is our last year, Sirius. After this, we have to go out and live our lives on our own." Lily could hear James or Sirius shuffling paper about on the desk top, and the heavy "flump" of a book being dropped onto the work surface.
"All the more reason to have a little fun now."
"All the more reason to work our hardest in class so that we're ready. There's a war, Sirius. And pulling pranks isn't helping anyone prepare."
Lily listened intently, almost too shocked to believe her ears. Was James Potter actually turning down the chance to cause havoc and instead opting to work on studying for a class that he aced without even trying? Apparently, Black shared her disbelief because he said, "I can't believe you, James. Just...see you back at the dorm." With that, the pair of feet closest to Lily got up and left.
Still under the table, Lily sat stunned for a moment. Not even a full month as Head Boy, and already Potter was toning down his childish tendencies. Lily hated to admit it, but she was impressed.
She found herself less impressed however, when she realized that she would have to eventually find a way out from under the desk, for it seemed as though James wasn't leaving any time soon. It took some stealthy crawling and quick reflexes, and she never would have made it had the Head Boy not been so immersed in studying (once again, she found herself impressed), but eventually she had been able to make it out, down a different aisle, straighten her clothes and return to her desk, pretending like she had been off getting a book. Aside from briefly looking up from his book to kindly smile at her, James didn't really acknowledge her. No date asking, no small talk making, nothing. Just his messy head bent over his scawled notes, his wand twirling expertly between his fingers.
Lily sat still for a moment, thinking. She glanced over at James a couple more times and his concentration on his studies never wavered (except for a moment when she felt like she almost caught him glancing at her). Yet again, Lily had to admit it. She was quite impressed.