>>13356154we don't question these things, anon, only accept them as incredible.
If you want a "real" answer though, evolutionarily, breasts became attached to motherhood because human mammary glands happened to be on the breast (as opposed to on the belly like a cow or anywhere else). Thus, since passing on one's genes is evolutionarily desireable, anything that increased fertility was hardwired into the human mind as attractive, the simple logic is something like this:
bigger breasts = more milk = healthier offspring = evolutionary success
Now bigger breasts = more milk may or may not be entirely true, but to even a simple mind, it can understandably seem true, so that is why women have evolved to gain ever-increasing breast sizes and men have thus evolutionarily gained an acute attraction for them.
That said, in the future, natural selection might become a thing of the past, what with genetic manipulation and all that. You could, in a century or so, say, "hey, instead of this flat chest, I want DD breasts" and have nanomachines already living inside of you slowly, manually replace the DNA within each and every one of your cells, and accelerate breast growth, so in maybe a month, you get precisely what you want out of your chest (or your entire body, if you want)
Why do I explain all of this in detail? I don't know, anon, I have some weird futurist fantasy where people can essentially shapeshift for sexual purposes using modern medicine.