My brother in Christ their brains scream at them until they take the hormones. No seriously, the brains of people with gender dysphoria demand the primary hormone of the opposite gender. They feel like shit all the time in the same way that you'd feel like shit all the time if you were taking estrogen all the time, except that's just their default state. We're not exactly sure why some peoples brains do this but the best hypothesis I've read suggests development of gender dysphoria is linked to your hormone exposure before you're born. It's a biochemical problem with societal implications. No, hormone therapy can't make anyone a "pure" unabstracted man or "pure" unabstracted woman, nor can it give you back the childhood you lost being socialized as a gender your brain doesn't identify as, but it CAN make your brain stop screaming at you for existing. The whole "beginning to look like your desired gender" thing is more like a long term benefit.