I came very late to the model train world, around the ageof 50 
My best friend since my early 20's was an avowed train nut and he copped YEARS of ribbing from me lol
I have however ALWAYS had a fascination for things of age, and from era's that highlighted the creativity of humans and as such have collected many things in my life even extending to early motorcycles ( I still own and ride occasionally my 1928 Triumph Model N DeLuxe! )
I found myself tho attracted to many things mechanical, so after a particularly nasty motorcycle accident in 2003 I found my lifestyle altered and my career pretty much ended due to injuries that have been and will continue to be degenerative. So I set about making a much simpler life for myself, consolidating things and planting myself on a small acreage in a fairly remote section of Victoria here in Australia ( the town I am part of has 6 residents lol )
As such I am indeed in a little timewarp and life is much simpler than the world would have you believe is possible. I suppose because of this to keep mentally active and interested in life, my mind turned to toys of a simpler time. I grew up not poor exactly, but did not have a wealth of toys etc so I coveted many of my peers and relations as they played with Mamod steam engines etc , something I knew I would never own...
Fast forward that 40 years later and as a disabled fellow living a frugal lifestyle, I found that I could indeed revisit my youth a little and set about finding and tinkering with the toys that had evaded me !
That lead to my desire for a Hornby Model Train Set , but it HAD to be clockwork 
( As the engineering , the period, just the "feel" of it was appealing to me )
Being a cheap arsed bugger I spent a fair while looking for a bargain, and when I found a set at a really good price I was overjoyed and snaffled it up immediately... from the moment of holding that locomotive in my hands I was hooked
Thus the challenge was set ... Lets collect the best, most varied, eclectic mixed bag of items I could afford , and again ALWAYS looking for the bargain in the rough, or the one that slipped under everyones radar and landed in my lap ... from humble beginnings came forth a love for all clockwork locos from the preriod before the cheap and nasty mass production of the 60's ( of course there are some quality items from that period that appeal as well tho , but you know what I mean)
Over the years I have been lucky enough to have sourced and acquired some amazing items ranging from a 1900's Ernst Planck locomotive thru to the late 50's with a personal affinity for French/European as well as very hard to find Australian offerings ...
So what do they mean to me?
A challenge?
The Joy of the hunt?
The opportunity to study, learn, appreciate?
Recognition and appreciation of the amazing ability of man to create design and manufacture things by hand?
Art? Social relevance? TOYS! ?
All of the above I guess , and an interest in life I can participate in when many of my old past-times have now proven too hard or painful to pursue
