When death is your business, you'd better get busy living.
It's the unwritten mantra that follows shinobi around between missions and brings down the average married age. If you don't do it now, there's no guarantee you'll be back to do it tomorrow.
Sakura notes, it's also what makes Konoha a village full of not just characters, but caricatures.
Being a Shinobi means living a life of nuance and restraint for the good of the village, on a mission, you are a carefully honed, much invested in tool. Excesses of personality are a liability in this line of work. Anything less than perfect efficiency and focus, Sakura knows, is enough to get to you killed. Or worse, it's enough to jeopardize the village.
To emote is a hard earned, off-duty privilege. So when the mission or the training is over and done with and you drag yourself through the gates and into the bar, all the parts of yourself you've repressed come springing back in full force into the small spaces you allow them. Over a lifetime of repression and compression, this is what creates the likes of Rock Lee and Naruto.
Or any of them really, herself included. Sakura knows that this is probably what magnifies her need for acceptance and her naïve obsession with love. This is what powers Hinata's staggering self-consciousness and Kakashi's staggering lack of self-consciousness. This is what fuels Shikamaru's passive nonchalance and Ino's aggressively terrifying vanity. After such careful practice and such tight control, no one has the energy to keep a rein on their natures anymore and so no one bothers. And no one realizes it.
As for the ones that do try to keep it all down, the ones who clamp down harder when the threats are gone, they've got it worst of all. Like a fist they can't unclench, they wind themselves up so tightly that eventually they cramp and bleed, giving way to Neji's frightening displays of anger, to the blinding obsession that makes Sasuke leave. It takes more than a full subscription of childhood horror stories to shape that kind of hate. It takes years of holding it all in, letting it build and build and build behind the perfectly stoney-faced facade of the perfectly blank ninja. It's a wonder, Sakura thinks, that their kind, the pre-sharingan-Kakashi brand of straight-edge ninja don't all spontaneously combust into little clouds of idiosyncratic confetti.
Being a shinobi is so much more than the jutsu and the reflexes, impressive as those may be. Sakura wonders what the civilians among them think of Shinobi, shinobi with their louder laughs and stronger drinks and more violent arguments (particularly when Sakura herself is involved, she'll admit). We are their undiluted conterparts, a full lifetime pressed into the periods between brief and debrief. A full lifetime compressed into a shorter life expectancy.
She like the way it is. Nobody seem to notice that shinobi live not just shorter lives, but more colorful ways. The village is a brighter place for it. All the feeling so carefully extracted from their village duties gets poured back wherever it'll fit. If this means more loyal friendships, more passionate romances, hell, more zany pranks and better sex, then Sakura decides, she's all for it.