I could think of better ways of spending my days than being made to share dinners, christmas, work, recreation and the building itself with thieves, wifebeaters, drug dealers and killers who don't have anything much to lose. And at the mercy of guards out of a San Quentin movie.
It may depend some on exactly where you go to jail, but... I know someone who spent a few months inside. For him -- though he was around 60 somewhere -- this is how it was: (And he hadn't even been convicted on actual violence charges to be placed there -- but some states only have so many places to "detain" people still undergoing trial, period.)
Tthe air conditioning was extremely cold at all hours, and something about it aggravated his respiratory problems to a near chronic state. The bedding was lumpy and uncomfortable, it aggravated his back problems. The food was insubstantial and rarely included fresh fruit or vegetables; it was pretty short on real, edible meat too -- much of what it did have was well out of date.
He was bullied by the guards and sometimes thrown in solitary confinement for the slightest complaint or bit of sarcasm (albeit partly, because people took it for a given that he was guilty of child abuse).
Reading materials of his choice were not available for some weeks after entering, until a lawyer or someone managed to deliver them. Then, they were later sometimes confiscated (along with some of his personal writing) in the name of "cleaning up" his cell when he says there was no unusual disorder to be found... Writing is only allowed with very short, dull pencils, because pens could supposedly count as weapons.
The actual medical care is limited by budget constraints, lack of supplies generally, substandard and outdated materials (much like the food), and doctors who are forced to accept that many patients with persistent issues, simply will not be allowed out of the facility to get even periodic care in real medical facilities which they really need.
And all that is before you get to personal threats, influence of gang violence or drugs and other contraband economies on the daily life in some facilities (though junk food taken from the prison store and distributed through inflated prices or demands for services, is one contraband that he considers vital in light of the food situation), and the matter of too frequently untouched sexual abuse -- which may make a nice fantasy, but I doubt you'd want to live with it for years without picking your partners and their kinks. He hinted that there was a fair bit of that, and he wasn't happy about it but people do it "to survive."/ digression on point of fact, but it's often not a lark, as far as I understand it.