The thing about part one Sakura, is that the anime kinda ruined her.
When I read part one in the manga, Sakura's development was obvious, because after each arc, she slowly came to be nicer to Naruto and not fangirl every second over Sasuke. Then, in the chunin exams her growth became very apparent, when she started supporting Naruto's dream, realized that she was no real ninja, but still willing to fight to protect her teammates, and wanting to beat Ino not merely because of Sasuke, but because Ino was someone she aspired to be like and surpass.
Sure, she still had her selfish love for Sasuke, but she was noticing more things and people than just him, like when she went to visit Lee in the hospital or when she was focusing on Naruto,during his fight with Neji, instead of just wondering about Sasuke. Not to mention her actions became less selfish, like when she was willing to run in front of Sasuke and Naruto, who were fighting on the roof and when she jumped in front of Sasuke, to prevent Gaara's attack from hurting him.
Her growth was natural and real in part one and the manga really showed it.
The anime on the other hand, hardly showed it at all. During the bench scene they added a moment of Sakura yelling at Naruto and calling him an idiot after she just promised she would be a bit nicer to him. During the wave mission SP edited out the scene where Sakura saved Naruto and what really made her development take a step back, were all those fillers. Because, all they showed were Sakura fangirling over Sasuke, beating up Naruto, and not caring about trying to become a real ninja, even though they happened after the chunin exams, where she started to get better in the manga.
That's why people are always saying part one Sakura was just annoying, because the anime did not portray her development properly and it looks like she didn't change, until part two finally rolled around. That's another reason why I dislike the anime, because it messes up the characters and is just too inaccurate to believe, so why even watch it, if it's not reliable? Part one Sakura may not have been the best character, but she was definitely not as bad as people are always making her out to be.