Definitely a passing interest.
My ex-Army engineer Dad was latterly a trucker, who took me on a few cross country trips as a nipper. Early supermarlet RDC pioneer, day/shift work, when it fit the ex-Army need to be part of something to be proud of, a national brand. He'd have hated what it became, with agencies and logistics contractors making it all feel a bit naff.
Maybe he'd have gone to another operator, but more likely he'd have done something even cooler. He was very cool, popular in the depot, big reason for me having such a fun and healthy upbringing, all those positive role models, a really tight group who loved a laugh. Definitely the cool one. Tanned, Ray bans, electric smile, Army fit, Army wit, not a typical trucker of that era.
So that's probably where my broad interest in transport and engineering comes from, but somehow, perhaps childhood travel needs, means my main interests are trains and buses. Detailed knowledge there, compared to only conversational trucking.
But I'll pick up the odd truck magazine now and then and read it with interest, even understand quite a bit of it. I know operators, types, makes, even a passable knowledge of operations, despite my dad's truck being the closest I ever got to the industry proper.
I have just two pictures, which I treasure. His rig parked up in our estate for a random (and presumably utterly unauthorised) home visit, and a pic of him at the depot hooking up the airlines taken by who knows, and who knows why.
Back then, even as a depot fleet, you could have your own truck allocated to you, its main or indeed only driver. We knew his truck due to one distinctive addition that was our secret. Made it sound magical, cool, but in reality, was probably a mere practicality to make his day easier when scanning for his truck in a packed yard. He was that guy.
He'd sometimes deliver to literally the nearest supermarket to our house and their depot. A notoriously difficult town centre drop. Wish I'd been old enough to watch him back it in. Mostly it was London multidrop, which makes his spotless driving record even more impressive.
Anything unusual will catch my eye. Love a heavy recovery rig. Love a steel truck. Love a showman's truck. Love a short urban trailer. Love a Volvo. Almost zero interest in heritage though. Albeit my interest begins with my dad's era, some thrity years ago now.
For a while there I was even snapping the things, but not as a spotter. Only the most interesting/photogenic (which is spotting!?!?), with a brief idea I could maybe get the whole set of a local steel carrier, given they occasionally park on the street outside their depot, my regular bike ride route. Not even close in the end.
Had a good few chats with some drivers of interesting looking rigs just randomly parked up. Seems a good life, better than most jobs. Not so good I've ever been tempted though. I think I already know I lack the discipline. Same for buses and trains.
I've been lucky enough to work in places where you could observe and even be quite close to trucks, so I'll often take a look, safely, and remind myself yet again, how bloody big the things are. I feel like I had a better grasp of how big the driving wheels of a Pacific are, well before I could tell someone with confidence, how high a fifth wheel is. You think you know from just being in the world, an adult allowed to drive near trucks even, until you're standing right there looking at one.
I've never been to a truckfest or museum, in contrast to the car museum mentioned above, once, and assorted bus and rail events and museums. But if there's a general motor transport show, I'll be drawn to the trucks after the buses, with almost zero interest in cars.
So yes, passing, definitely.