Forty-seven, or, last year. 
Three years old in 1956
When I was around 8 years old my uncle gave me a big Lionel train set. I’ve been interested ever since.
I don’t remember not having trains! In fact, my dad used to tell me my favorite bedtime story was one of those books that had pictures of different rolling stock in it with a little description of each lol.
My first train that I remember was from the back of a cereal box when I was 5. My folks let me play with my Dad’s old Ives set when I was 6, and a Lionel set followed when I was 7. I went over the edge when I was 15 and got into HO trains.
I have loved trains and had toys since childhood, but I only discovered the hobby of scale model railroading and layout building in my mid 20’s.
Ron
When I was a kid…5/6/7/ (1975, 76, 77), my grandparents used to take me to the “Hump” over @ the ex-Conrail, now CSX Yard in DeWitt NY. We’d sit there watching those engines pu***he cars up the hill, then wooosh… down the incline they went and onto the fingers they had to be on. Then when i was about 11 / 12ish, my dad got me a O27 Santa Fe set. When the engine died, he got me a E/L A/B set to usee for pulling my cars around the tabletop. I got out of the hobby when I was in HS…only cause I didn’t need any g/f’s laughing at me for it. Got back into the hobby about 3 years ago (I just turned 33 3 months ago) - HO Scale - and am now in the process of building my 1st layout - about 9’ x9" ‘C’ shaped.
I have an old home movie, Christmas '68 which shows me at 2 running the HO loop around the tree. That’s the earliest proof I have.
I was 8 when I got my first 3-rail train set, and was 13 when I bought my first Model Railroader magazine in 1967.
And I’m having more fun than ever in the hobby today, almost 40 years later …
from Birth on… my father and grandfather both loved trains. Lionel, HO late N and G. So… 34 years of lovin trains!
Lots of kit building from grade school on, but only a love for trains
Model Railroading
First time: 25 (no money, no space, no time)
Second time: 58 (still no money, lots of space, lots of time)[:D]
I was 3 when I got my first train set. We ended up moving to Texas so my parents could get a room for my trains (that is what they tell people). 30+ years later I am finally building a layout I have dreamed of since then.
I started running my dad’s O scale 2 trains rail at age 3…
I got a train set when I was twelve years old, and I added some track, more freight cars and a couple locos. I was somewhat serious about it - I even bought a couple of issues of Model Railroader and Trains magazines. But after a year of ‘railoading’ I gave it up for rock ‘n’ roll. I got back into model railroading when I was 20, and I’ve remained a model railroader ever since.
My earliest memory–of any kind–is of watching trains in England when I was three years old! I started reading MR when I was thirteen, and dabbled in the hobby through my teen years. I got serious about building a layout four years ago, at the age of 39.
I have been involved in this hobby since day one, thanks to my Dad. He grew up watching the very end of steam on the CNW and he was hooked. He spread the hobby to my and my two older brothers. So for me 28 years and counting.
I got interested in Trains at the age of 2 ( I turned 13 today ) and strated with electric trains at the age of 7 been in 'seriouse " modeling for about a year and a half.
I remember my first HO scale set when I was three. My dad built a simple figure eight and the wheels of othe 0-8-0 made sparks were made when it went over the crossing.
I was 7 years old and 50 years later, I still love trains
the day i was born now i am 12