Prior to HRT (and a brief period I suspeneded taking anything when I changed jobs...dumb!), I had not sensation in my chest area that was different than anywhere else for most of my physiology.
After being on HRT for about half a year, I now understand why they are called mammary glands. Oy...I think they feel more tender and impact me more than the 2 unwanted bits down below. I have to say...I love the the feeling. It just feels right.

And prior to HRT, I never understand female arousal and how breasts tie in. I can say honestly now, that I can become aroused just by doing a self-inspection with no errotic thoughts on my mind. It's like my body is on auto getting me ready. What a wonder, wonder feeling and it's so...I don't know, mystic in the way hormones rewire the brain to respond to stimuli.