Looks like MTMTE Part 1 aired September 17th 1984. I would have been 8 years (and 5 months) old.
I remember catching a blurb on the news my father was watching about the new toy robot miniseries.
I don't remember for sure but I was a huge Cartoon kid so I expect I was glued to the TV for the premier I remember being very excited for things like that. Cartoon miniseries or specials were big in the early 80s. Care Bears. Strawberry Shortcake. Rainbow Bright. All started that way. The several Joe miniseries before they became a regular show too of course. I would watch commercials, annual Fall Saturday Morning Cartoon previews and look through my parents TV Guide magazines. I was locked in on Cartoons and Toys so I was there for the G1 toon from the start.
While I can't say for sure I expect I probably had at least some toys already before the cartoon. I got Brawn very early (although after GoBots Spay-C my first Transforming robot). I know I had Bluestreak early and Laserbeak+Frenzy. Frenzy will always be the blue one to me because I had him well before the show. (Eventually had a bunch of Laserbeaks because the local toy store sold individual microman (or knock off) tapes.) I wouldn't have had Optimus Prime yet because he was a Christmas 84 gift.
-ZacWilliam, also had Ironhide pretty early and Diakron red Sunstreaker those might predate the show too.
About 2 & a half when it started in the US, I think, thou there was a lag of a while before it appeared on UK TVs, but my first ep was Fire in the Sky where Skyfire debut, the ep just kind of burned into my mind, at least that scene where he takes out Starscream, its one of my oldest memories along with getting Seaspray as a toy, I wanted to see more but back then, I didn't know the conspect of TV shedules, so I kind of relied on video rentals to see bits of TF including the movie, thou I did see a bit of the Return of Optimus prime on TV and Rebirth, thou my first full TF series is actually Beast Machines as it appeared on Fox Kids, while Beast Wars was on Channel 5 and airring only in the Sunday mornings, early for me, thus I only saw odd bits of it, while BM was airring much later in the day and I was learning the idea of shedules for TV programs, it would be years later that I actually see all of G1 & BW, then there is RID2001 which is sort of a series I genuinely love, BM is good in my eyes but RID was just a lot of fun with all of its colourful characters! Other shows from the 80s, Jayce and the Wheeled Warriors (this show seriously should get a revival) saw a bit of MOTU, but don't recall much of it, saw Thundercats as well, MOTU was forgettable to me, Thundercats, that theme song gets in your head, a massive chunk of my childhood shows were not Disney, Disney kind of entered my life in later years when some of their movies came onto VHS tapes and my parents bought them
I would have been almost 3 1/2 when the original series premiered. I can pretty confidently say by the time I was 4, I was hooked on Transformers, GI Joe, and Gobots. It was a good time to be a kid. Maybe not a great time to be a parent, though.