I believe I started to experience what you describe after a few weeks on E. It just felt right. I could feel my nipples getting sore, colors were more vivid, it seemed like I was starting to feel my emotions more deeply or perhaps just in a fundamentally different way....it was wonderful. Now if only truly horrendous outside circumstances hadn't prevented me from stopping...gosh...if I hadn't been forced to stop after only a month, I would've been on E/anti-androgen for nearly 14 months now... *sigh* oh well....life happens, there's no other way it could've played out. I needed more soul searching time and to recover emotionally from a tremendous bipolar manic episode.
on the bright side, although I'm not on HRT now, I know beyond a doubt that it's what I want, I know who I am...things were pretty unclear and muddy when you have extreme gender dysphoria and severe bipolar disorder at the same time....the bipolar stuff just needed to be sorted out before moving forward. anyway I'm ranting now...E was absolutely wonderful, and yes, I did have feelings of completeness while I was on it.