My husband only really discovered he had "parts" a few years ago, but looking back there's a sense in which he always knew. It was more that he was aware he would "click out" .. particularly when angry/threatened, etc. But it wasn't until about 6-7 years ago he told me "I think I have a girl in me." (That part we would come to call "Femmy" and it's a younger, age-sliding part who likes more traditionally "feminine" things - he's also the softer, kinder, romantic, and artistic side of my husband.) It wasn't until we were transitioning from "best friends" to "more than friends" that he actually "switched" in front of me - and more than once, and we began to really investigate what was going on, how his "internal world" was structured and functioned, etc. He knew he was classed among "voice hearers" but he didn't know anything about DID or DDNOS etc.
Context - my husband was well over the age of 40 before having this revelation and insight into himself, so he spent MANY years literally "running away" .. he only thought he was crazy, found himself in repeatedly threatening situations, and would relocate roughly every 18 months of his adult whenever he thought the people nearest to him were starting to "suspect" he was crazy .. He'd been to many counselors/therapists, he knew his "issues" were related to developmental traumas, but he never confessed enough to any of those counselors/therapists for them to get close enough to a diagnosis - he was ashamed of his struggles so hid a lot of his reality from the outside world.
NOW, he is what we could call a "healthy multiple" .. his parts are pronounced but not necessarily fully formed "persons" - there are times when they are more present than others, and he still "switches" but HE - the person we think of as primarily my husband - is always WITH whomever might be "out" at the time. So in clinical terms he's primarily co-conscious. He has developed solid/reliable internal communication and cooperation, and we've identified (so far) basically 5 "parts" inside .. we have names for each of them though they don't have names for themselves, and my husband is the most "in charge" of their system, though "Grumpy" gives the orders internally .. because job #1 is to keep himself safe, so Grumpy "orders" my husband around to this end (like - double check the locks on the back door; turn off that burner; hang the keys on the nail - cuz I'm so sick of you forgetting where you placed them!, etc.) ... All in all, we very well KNOW everyone inside, I love every part of my husband, and he knows every part of himself loves me in their own ways. I "adapt" depending on who I am with, but this comes very naturally to me most of the time .. so we really work well together!
It took us years to get to this point, but considering how many DECADES he lost in his earlier life, we think this past 4 years or so has been the BEST part of his journey, even though it's been hard. He is FREE to really BE himself, and inside our relationship, LOVE is what keeps us both safe - even in the every day kurfuffles, that love is unwavering. It took years for him to develop confidence in that, too - and we didn't marry UNTIL he was in "internal agreement" about that ..
He's an AMAZING man .. he has gained a lot of WISDOM in areas of life that he might not have otherwise encountered because he had to "figure things out" so on his own. He still comes across as an "extreme" or "intense" person to other people sometimes, but he very faithfully "rescues" them with humor most of the time, as long as there's not a "threat" in the picture. :)
Anywhoo - If you care to share more questions along this line, I'd be glad to post more. I'm not sure if all this gets at the heart of your REAL question, but I hope it's at least an encouragement!!
~WU