I had a modest HO gauge train setup, which started out with a Tri-ang set and grew from that.
My layout was on a 6' x 4' piece of chipboard which made it "portable". This, and the fact I lived 4 doors down from my (primary) school meant it was a candidate for inclusion in the school's hobby display at their annual fete. I would go home with 3 other kids and we would carry it up the street to the school. I'd then set it up and guard it for the duration.
When not in use, it could be stood on edge, since there was no high profile scenery - and this became a problem. As the years passed and the interest waned as other things took to the stage, the board was relegated to the garage - and one day, after a particularly nasty rain storm, water had seeped across the garage floor ... only stopped by the sponge that my train set baseboard became. I only discovered this some time later and the resulting mess was very disheartening. I had tacks used to secure the track to the board rusted in place and crumbling wood fibres everywhere. The board was tossed and the track was mostly rescued - but some of it was not looking too wonderful. Since that day, it has been packed away. It has been well over 20 years since any of the rolling stock rolled anywhere, so I would want to check things out before running anything.
I would also need to redesign a layout. After it's last use, I came across some bargain track at a garage sale ... that I just couldn't pass up. It had at least 4 yard long straights plus some other pieces - and I don't know where that all ended up. But I am also going to have to have a serious look at some of my original track. I did a stupid thing. Having some problems with good electrical contact with the rails, some bright spark suggested I give then a rub with some fine sandpaper. Being young and not knowing any better ... I did. This worked well - for a very short time, since I had removed the plating on the tracks and the tarnish I had to deal with before had been replaced with rust. Some things we learn the hard way.
Will I ever resurrect the set? I don't know. My kids have never seen it run - and I'm not sure if they even know I have it ... and now there are grandchildren on the scene - but they are a bit young yet.