My point of view as a survivor of two years worth of sexual assaults as a child.
If your past affects how you react to things today, then explaining that to people close to you can be a massive relief.
"I find it upsetting to watch TV programmes with sexual violence in them, because I'm a survivor of rape" for example. Rather than just sitting there on the settee feeling trapped into silence, desperately wanting to switch the channel but not being able to think of a reason to do so. Then spending the next 12-72 hours in a rictus of strained muscles because you're fighting off constant flashbacks. Not being able to explain to your partner why today you can't bear them to cuddle you in bed whereas yesterday it was fine.
Being open about what you've survived is a very freeing thing. Often as survivors we have built walls of silence around us and we think those walls protect us. What they actually do is isolate us and prevent us from getting the support we need. Every time you say to someone "I was raped" or "I was molested", you're taking a brick out of that wall.
Don't get me wrong, it's fucking terrifying at first, because we've been conditioned to believe that we should be ashamed for being victims. That anyone we tell will throw up their hands and go "Eurgh!" or ask "Why didn't you fight him off?"
(If you get that last reaction, you know you're talking to a complete twat and you can then just not bother ever talking to them again.)
For all the times I've been open and said "Yes I'm a survivor of child sexual abuse" I have not really had any negative reactions at all. Some people just go "Erm" and quite clearly don't know what to say, but that's their problem, not mine. Most people are immediately supportive. Nobody has ever asked me to tell them the details, or to justify anything.
The most rewarding thing about being open like this is when someone approaches you privately afterwards and discloses that they too are a survivor, and they wish they were brave enough to speak about it, and that you've made them think maybe they shouldn't be ashamed.
I had one guy - my last LTR actually - who said he had never met a rape survivor before.
I said "How many women do you know on a more than acquaintance level? How many women colleagues and clients do you have? How many women are in your family - your mum, sisters, all your many cousins? How many women friends outside of that? How much do you think all that adds up to?"
He thought for a minute and said "I suppose about 100, why?"
I said "Then statistically, you know at least 10 survivors of rape or sexual assault. You just don't know that you know them."
He was gobsmacked. He'd never really thought about sexual violence before, because he didn't think he knew anyone it affected. It totally changed his attitudes.