Me too (without a hashtag, thanks). Same age as you, same dawning of realisation. Although different reason.
My 'light bulb' moment was over narc sibling trying to grab my inheritance. Also changing tack and making several attempts to steer my inheritance away from me and towards them. Which resulted in me having to wake up and catch up, which I did.
I told narc sibling exactly what I thought of them and what they were doing. I got a suitably high handed put down for a response. However, it did the trick. Also, in hindsight, their lack of proper response was the unspoken, 'I got nothin'.'
It's a very long, complicated, boring story however, I did start reading up about why do they do that ?
That's when I learned that it's part of narcists behaviour to steer legacies in their direction. I also learned, 'write a letter to the narcissist, stand over their grave and read it, then you will understand why they are ignoring you.'
So much of their behaviour growing up fell into place. When I've read about narcissists on this site and on other places, it's chilling that their dialogue is identical i.e. you're embarrassing yourself. That's one of their little put downs.
Here's an example: a MN contributor caught her boyfriend flirting with someone else in the pub. She confronted him in the car park of said pub and got told, 'you're embarrassing yourself.'
Other people have remarked that there must be a narc handbook that they all use.
Narcs are obsessed with money and status. Well spending to impress (themselves mostly.) Yeah, my narc sibling did this and ended up re-mortgaging the house to clear their debts. All with the associated drama, of course.
The lying i.e. can't tell me exactly what happened so thought they'd give me a drama story to get sympathy for them being in the shit due to their own actions.
Tried to come between me and surviving parent i.e. they seem to think they were orchestrating my relationship with surviving parent. Believe me they weren't.
Gave me another load of old toffee about surviving parent threatening not to come to my milestone birthday tea and had to recruit a long standing friend of the family to talk sense into him.
All textbook narc behaviour, because it's all about control. It's all about getting the 'victim' on the back foot and questioning themselves. Also the, smear campaigns they do as well. She smeared surviving parent to me. So, vice versa too I expect.
I have, at last, learned their 'story telling' voice. It's their, 'I'm telling you this as a friend' voice or their, 'I'm telling you in this in confidence' voice or their, 'this is interesting' voice. Anything where I catch myself being, 'all ears' when I'm listening.
Most recent example was at an ash scattering ceremony where they remarked that a random person had remarked that both families could take half each of the ashes. I made my appropriate and civil reply.
That was just their way of saying, 'too bad the ashes could not be split equally then we would not have had to see each other again.' (Those would be the ashes you couldn't collect fast enough from the undertakers to make sure you had possession of same.)
See what I mean ? Always got to be some story or drama but said in such velvet tones. It's taken me until middle age to get this and other indicators which I found through researching narcissist traits. I've got the gist of it, that's all I need.
The only good thing, is, that their behaviour is, at least, predictable to me now. That there WILL be a hoovering. So called because they try to suck you back in. Yep, that's what's currently happening.
I always wondered why narc sibling could be such an arsehole then be genuinely reasonable and listen properly. You know, after the fact when the matter was safely in the past and could not now be changed.
That, I learned, is hoovering. AKA the hoover manoeuvre. When this happens like you would want to yell at the subjects of a horror movie, 'RUN !'
I understand what 'grey rock' is and that's where I am with them. I'm low contact with them. Obligatory greeting cards twice a year but that's it. There's no love lost on either side.