Congrats on your new friend! He does look little for his age, and he's so lucky you found him!
I had to chime in because it reminds me so much of my little guy, and his nickname I call him is "Buggy".
I was heading down the 4 lane highway one summer day in 2009, going about 70mph, and I see this little gray fluffball blur out the corner of my eye. People never can believe how I can spot things, it's just been a knack I have I guess. Anyway, I called my husband as I was turning around and I told him I swear I just seen a tiny baby kitten on the highway! It was on the painted line that divides the shoulder from the inside "fast" lane people drive in. I was in a huge hurry to get back there, because it was inches from car tires on this busy highway!
Amazingly, I got back to him, picked up him and he was ALIVE and in apparent good health, aside from some dust in his eyes from the cars flying by. He was too young to walk, he just crawled, couldn't have been more than 4-5 wks old. Here is a picture of him in my husband's hands as soon as I got home: (WARNING: THIS PIC WILL MELT YOUR HEART)
Two weeks later:
And he's about 2.5 yrs old now:
It's still a miracle that he survived, however he ended up there. He wasn't injured at all, but there were no farms anywhere nearby. There was a factory about a 1/2 mile from there and that was it. His history is a bit of a mystery, but as you can see, he's alive and well today! He's quite the trouble maker actually!
I'm sure your kitty is also delighted to have a safe, loving home!