It's hard to imagine an experience you haven't had. Either one you're about to go through, or one you likely never will.

When I came out as trans, I read about (and heard people talk about) the kind of reactions I could expect from friends and family as I came out to them. Most are the kind you'd expect, but the closer a person is to you, the more intense and unpredictable the reaction can be.

Part of the reason for this is something that I wholesale rejected - really despised - at the time I first heard about it. That concept is grief over loss.

I heard it described as something relatively common when coming out to parents - that the process can be not dissimilar to flat out losing a son or daughter, even while and gaining another child. That the person goes through grief.

At the time, my rejection of this and annoyance at it came from hating, really hating, the idea that peoples' relationships with me was that gendered. I was preferring the idea of living in a slightly naive world where people are friends with me, not a gender performance or a beard or a really specific kind of behaviour.

On another level, as the months have passed, I've had to realise and accept that in a lot of ways I didn't fully understand the intensity of what I was doing. I was naive about that too. I wanted to feel that "nothing would change". That my friends would remain my friends, my family my family, and that'd be that. Because I felt I knew they were clearly all mature and intelligent enough to not judge me or treat me differently based on gender. And while that has predominantly been true, I really feel I didn't understand just how much I would change.

When I hit the point of accepting my gender dissonance, and realising how much of my life was and always had been totally wrecked by the astoundingly shit experience of gender dysphoria, I was at my wit's end. I finally recognised and accepted a problem I'd been actively denying for years, and knew I had to change it.

Of course, that hasn't changed. On a fundamental level I am happier now than I've ever been, and the degree of comfort I have with myself is hard to describe. I made the right choice.

But I didn't realise how much of my own experience changing would affect my world, and how much of a shift (hopefully in positive ways) there'd be in my personality.

I often see friends - trans or cis - using metaphors to describe transitioning. One of my favourites early on was regenerating. Like Doctor Who. I loved the idea because it seemed powerful and cool. If you're going to go through something this massive, likening yourself to a benevolent long-lived Loki-like god-figure helps make the idea seem less scary.

The fact is it's a much longer process, but one way the metaphor really worked in a way I didn't expect was that The Doctor's personality changes, just as mine has changed.

Which brings me back to grief - the reaction I read about that I had rejected and hated the very idea of.

I underestimated just how much this (relatively) fast change could affect the way someone related to me, and I to them.

Whether it's because of hormonal shifts affecting my emotional reactions, because physical changes on this scale can't help but affect the way even the most well-meaning friend treats you, or because the way I an treated socially has affected how I view and react to even close friends.

It may sound like I'm just talking about or focusing on men here ("it's weird to think that you're a chick now", etc) but it's not exclusive to one gender identification.

The process of transitioning has been, for me, an exercise is self-discovery and re-learning a lot about myself. I'd made so many assumptions that were wrong, surprising me even though I went into this trying to jettison any ideas of who I was.

And the more I realise I change, the more that grief actually seems like a reasonable and understandable reaction.

I found the idea of "you're a new person now" laughable because my conceptions of the importance of gender identification and performance now feel wrong, but they make an enormous impact in how the world treats you, whether it's strangers or friends. This isn't all negative - many of my experiences have been overwhelmingly positive. And I'm not trying to cry that gender is anything other than the enormously complicated spectrum it is, either. I've certainly had a hugely different set of reactions from friends depending on where they sit. Not all women are enormously feminine, and not all men are enormously masculine.

Some people I know were instantly and obviously a little uncomfortable. They seemed to sense that I would change, and this scared or concerned them a bit. (I don't mean that they were transphobic - just that for some people recognised better than me how big a change this would be.) Others weren't obviously concerned, but seemed to become so as they saw me change.

I'm not criticising any of these reactions. If you've never had a friend transition, and never transitioned yourself, it's naturally outside the breadth of your personal experience and can be any combination of surprising, scary and even fascinating.

I'm not upset with myself for failing to accept the enormity of all this - although I do wonder how much was ignorance and how much was a desperate desire not to let myself be lost in just how massive the coming years would be.

I do, however, recognise that I underestimated hugely how big this would be for my friends. Especially now that I have more trans friends who I've seen, however briefly, go through their own transitions, I realised what a massive deal this makes.

It isn't the right place for me to unpack how much of this is hormonal and how much is social, but which percentage is what doesn't really matter.

Fact is when I think back to past behaviour and memories, it's quite foreign. Like the memories aren't mine, but implanted, Blade Runner style.

They happened, and I remember them clearly (in some classes more clearly) but as I've spoken about before, it's like they happened to someone different.

And I suppose in a very real way they did.

The 'regeneration' metaphor seems more apt than I ever imagined.

As I change I've found myself closer to some friends and further away from others, and it's nobody's fault - nor is it permanent.

Something else I've realised is that it takes time to reconnect with friends - because that's literally what you have to do. Your interests may be largely the same, but the tiny changes add up and it can take a while to find the core of your friendship again.

To those I've barely seen, it might seem I'm more distant, and to me it might feel that you're more distant.

I try to think of this another way, though: that it means someone I know I can be close friends with, I get to experience becoming friends with, again, for the very first time.

And if you feel the way I described earlier... I think I get it now. And I'm sorry for your loss. (Let's just hope the 2nd Doctor continues to be less of a grumpy shitcake than the 1st.)