You know I just remembered this : I was just on the verge of going full-time, about four months on hormones, yet occasionally I had to go out as a boy. Things up top were definitely sore!
So I go to my meeting and this fellow who I hadn't seen in about a year comes up and does something I don't miss moron guys doing...he says "Hey long time no see!
Titty twister!". Grabs my nipples, and twists. Holy crap I go *AHHHHHHHHHHH!!*

and I went
straight down on in a room full of people!
At least he was equally surprised! Hopefully he learned to be a little less obnoxious.
Also about breasts...it is true to be careful. The other day I ran out to my car and took a jarring step. I wasn't wearing a bra and they go *ba-boom* and recoil. My right boob hurt so bad for like ten minutes, and I didn't even hit it on anything!

I must say though overall they really are very nice thing to have, and I hope you enjoy them!