Well to be fair scientific evidence for gender dysphoria exists, though I assume the point being made is the whole "girls body" part sounds off, since a really basic way to explain gender dysphoria is that mentally you identify as one gender, but your physical body is that of one you do NOT identify as, i.e. being born with a body that's a "male" body, but mentally you identify as female.

Going on hormones and possibly going through sex reassignment surgery (not everyone does surgery, with one big reason usually being monetary issues) are some of the biggest ways to treat gender dysphoria since they're two of the biggest ways to help one's physical body match up with their mental gender identity.

That fact wasn't very fun.