This is your more-or-less daily reminder that sex is physically painful for some people with vaginas, and this is sometimes because of inconsiderate/inept partners or lack of education, and sometimes really not.
Things that can cause this include: endometriosis, interstitial cystitis, ovarian cysts, vaginismus, vulvar vesitubulitis, scar tissue, low estrogen, various infections, and many more factors.
It’s important to say “if sex hurts, this is a legitimate problem and there are things you can do about it” as part of sex ed, but increasingly I see this being oversimplified into “sex should never hurt if you use enough patience and lube,” and that’s really not an okay simplification to make. It makes this into a sexual performance issue (or even a political one) when it may well be a medical issue.
Patience and lube are definitely the first things to try—hell, you should probably try them even if things don’t hurt, they’re pretty awesome—but could everybody please stop spreading this misinformation that underpreparation is the only reason sex could possibly hurt?