Until relatively recently, I was treated as a white, heterosexual male in a socially-acceptable, long-term relationship with a woman. There's a level of invisibility that goes with that which is easy to dismiss, or take for granted.

Yet I was surrounded with people who for whatever reason - different background, gender presentation, same-sex partner, etc - didn't have that invisibility.

It may be a relatively (and increasingly) progressive society I and my geographically-close friends live in, but there are still aspects of their lives which were wildly different to mine.

Yet I thought I understood. Not completely, of course - but in general. I felt anger when I heard that a friend had suffered homophobia or sexism while out in public. I tried to put myself in the headspace of what they have to go through.

I thought I was, at least in the past few years, fairly good at it. I knew I didn't fully 'get' what it must feel like, but I still thought I had a pretty good idea. That my imagination could do the work, and where it couldn't - just listen to what others said.

I didn't always do that. I was a total shit for years, slowly maturing and learning that just listening to others whose experiences are different is a really damn important thing.

I thought I had some understanding of what I was in for when I began hormone therapy. I'd seen "casual" sexism, homophobia and even a limited amount of transphobia, or at least heard about it first-hand from friends who'd experienced it.

The upshot of this was that when a discussion about sexism or some other form of systemic prejudice came about, I could detach myself from the emotion of it and discuss it dryly and dispassionately. I could attempt to empathise with the scared, clueless, ill-educated people who mocked and abused my friends, having discussions about potential ways to deal with this problem long-term.

I considered this a strength. "I don't get emotional about this, which means I have an advantage over people who actually have to face it on a daily basis" was what I genuinely thought in my early to mid '20s. I didn't consider myself 'better', but I was one step short of that. I had no idea I'd so clearly bought into some of the worst, most insidious parts of the way our culture treats bigotry and bias.

Then I began hormone therapy, and things began to change. In retrospect, it was incredibly fast, but at the time it seems almost glacial.

But key moments happened and they were horrifying to experience.

The first time I had someone yell "t**y" at me as I was out and about made me feel so incredibly small and worthless, I went home and cried for hours. I didn't ever want to leave my room again.

Having "dyke bitches" called out when engaging in an innocent public display of affection with a female partner wasn't quite so bad, but it still chipped away.

Then, once I began to gain the privilege of 'passing' as a cis woman, the general transphobia may have reduced but I began to suffer frequent sexism, and I hadn't even begun to imagine how much that'd hurt. How insignificant, nervous and even scared it made me.

I remember walking with a friend maybe eighteen months ago. Some slightly-drunken shit swerved slightly too close to us and made a dismissive, objectifying comment about her breasts (in Spanish, no less) before veering back off and leaving us alone. It was over in a second.

My reaction was to raise an eyebrow, shocked at the strangeness of it happening.

She went quiet for the rest of the morning.

I genuinely couldn't comprehend what that feels like.

I realise now what a complete failure of empathy I'd had through most of my life.

That feeling angry and defensive and even either wanting to or ACTUALLY standing up for my friends when I saw them suffer racism, sexism or any other bigotry in public was not even close to the feeling of being the target.

It's made me feel very differently about all this.

I see the very personal anger, hurt and (unfortunately) shame I feel when I suffer even minor abuse... as a strength. A constant motivator. That things should be better.

More than this, it's also stopped me assuming I understand things I don't.

I could easily just go, "well, getting racist abuse hurled at you must feel much the same as getting sexist, homophobic or transphobic abuse hurled at you, so therefore I understand".

But I don't. I can't. I won't pretend to understand things I don't know. If I am forced to, I simply have to assume it produces some degree of similar psychological effects because I simply have no other basis for comparison, but I won't assume I can understand it as a result.

I can't. I won't ever understand what a lot of these things feel like, and I accept that now. I try to let others talk, and if I have a way of signal-boosting what they say, then so much the better.

It's humbling to realise how wrong and how arrogant I was.

I spent much of my life suffering from a catastrophic failure of empathy, made worse by its total invisibility to me.

I think back to that incident now with the Spanish-Breast-Objectifier and I wish I'd taken it more seriously. I wish I'd said something. I wish I'd asked, "Are you okay?" I wish I'd shown honestly that I may not have understood, but I did recognise this fact.

It's the least I could have done, and I couldn't even manage that.

It may not have helped much, but it's something.

I think of similar incidents happening to me now, and I know this: when it happens - when I suffer some seemingly-minor sexist or other bigoted comment (well, 'minor' when you aren't the target) from someone and nothing compassionate is said by nearby friends... it adds to a sense of loneliness that builds up over time.

I wish I'd understood this then.