I made my first edit as a registered user (#169,140) on 26 June 2005.
I originally did my editing (42,000+ edits) with another ID (now User:Before My Ken), but because of wikihounding which I felt could not be effectively handled by the state of interpretation of Wikipedia policy at the time, I changed IDs to avoid the harrassment. With a second ID (now User:Between My Ken) I had very negative interactions with a sockfarm attempting to control the content of various pages connected to an independent film, and I changed to my current (and final) ID, User:Beyond My Ken. After I filed the initial SPI on the puppetmaster, User:Sorrywrongnumber, one of their socks filed a retaliatory SPI on me. As a result of the positive checkuser result, my accounts were blocked, but after a subsequent discussion on AN/I I was allowed to continue editing under this account. The other accounts were redirected to my current user and talk pages, and were blocked.
I want to be clear that although I have had more than one account in my time on Wikipedia, I have never, with the trivial exception of a few housekeeping edits to my original account, used more than one account at a time, and once I stopped using an account I did not go back to it. What I did could best be described as "using serial accounts". The user and user talk pages of "Before My Ken" and "Between My Ken" now redirect to my current pages.
Regarding "Ken"
It's a natural mistake to make, but "Ken" in "Beyond My Ken" is not short for the name "Kenneth". It is the English word "ken", derived from Scottish, and meaning "knowledge". My given name is something else entirely, so "Beyond My Ken" or "BMK" are appropriate names for addressing me here on Wikipedia. (And, yes, I am entirely aware that by choosing this username, I opened myself up for smart-alecky remarks from editors who disagree with my edits.)
"So you don't forget, order before midnight tonight..."
For what it's worth, although for a while I used "BMK" as a signature, and I am often referred to colloquially as "BMK", I am neither User:BMK nor User:Bmk.
That issue
Since it has come up a couple of times, I should say something about my professional connections.
I am a freelance theatrical stage manager. As such, I have worked with numerous companies on numerous projects, on Broadway, off-Broadway, off-off-Broadway, in Europe, Asia and in regional theatres across the United States. Because of this, in my 40+ year career, I have worked with very, very many actors, musicians, dancers, directors, designers, choreographers, playwrights, songwriters, producers, and presenters. I have contributed to the articles on some of these people but never at their direction or on their behalf; most of them are not even aware that I have done so, or that I am a contributor to Wikipedia. Even more importantly (to me, at least) is that I have never revealed anything that I was told in confidence, that I found out in a private circumstance, or which was simply theatrical scuttle-butt (of which there is a lot).
I have used my knowledge to know where to search for reliable sources of information to enhance those articles, but I have never been paid one red cent for my work, I have never made an edit for anyone or suggested by anyone or even alluded to by them, and I always uphold WP:NPOV, WP:V and WP:RS
Given this, the notion that I have a "conflict of interest" regarding this large number of people and institutions I've been privileged to work for, or that I am by any definition a "paid editor", is ludicrous. Every single one of my edits will stand up to intense scrutiny, despite the scurrilous accusations and unsupported aspersions that have been directed at me by anonymous individuals with a bone to pick and their own checkered Wikipedia history.
Warning! Warning! Danger, Will Robinson!
Another editor has called me "The worst thing to ever happen to Wikipedia."
You have been warned.
Re-evaluation
After an unpleasant ANI discussion in March 2019, full of untruths, personal attacks, and misinterpretations (some of them clearly deliberate), I voluntarily agreed to an editing restriction. I also decided, after almost 14 years on the project, to re-evaluate my connection and commitment to Wikipedia, and radically pulled back from the volume of editing I had previously sustained. I have not left the project, and I have never stopped editing completely, but I am trying to understand whether the toxicity of (parts of) the community and the mental and emotional anguish they cause are worth the time, energy and involvement I put into Wikipedia. That evaluation is ongoing, and my decision, when I make it, will become obvious in the volume of my editing.
November 2022: Obviously, I'm back to editing pretty regularly, although with less volume of edits than in the past. The Wikipedia experience seems to lend itself to many editors taking periodic "time outs", and to some of them cutting loose entirely. I'll leave it to a professional sociologist or anthropologist studying the culture here to determine why that is (I suspect that anonymity plays a significant role), but the fact of it seems beyond question.
Thoughts
For a record of my thoughts about Wikipedia over the years, please see this.