Oh well, I'm sure plenty of us have been there. I know I have.
My first 2.5N/A Defender on crap old ATs I took down to a greenlane well into winter, pointed it into a rut on my mate's advice (it was a Landy after all) and just sank into the clay.
Took a tractor and a £50 bride for a farmer to pull me out, red faced and all.
I was 19 then, I bought a Tirfor and accessories a week later.