Aye, if you get that nice clay that's all filled with rocks and very tight it's a pain to dig. There's even a word for it thought I don't think there's an english word for it though.
That said. I did dig ten meters 50cm deep 40cm wide in that kind of ground in five hours or so. Then again, I've been digging way too many ditches since youth. Oh the joy!
"Hey, we need an electric cable to set up our new garden lights."
"No problem, son's got nothing planned for this weekend."
"WHAT! It's november! The ground frozen already!"
*Ominous glare that promises to keep me grounded and without any pc for the next month*
"Fine, I quess I'll call her I'm not coming..."
What saved me was mp3 player filled with Nightcore!

Man I really loved that mp3 player. *sniff*
Now it's gone. Died last january. *baaaw*
Good old Creative(128mb), you had good 8 years... *sets flowers on grave*