Your 10,000th day alive. You'll reach your Tkday when you're about 27 years, 3 months and 15 days.
It's a big day. You've finally moved from being a four figure day person to a five figure day person and you'll always now be a five figure day person.
On you're Tkday you actually become an adult. Forget 16th, 18th or 21st birthdays - you don't actually know anything then. But on your Tkday you should really have worked out that life's a bit tricky and things aren't going to work out exactly as you'd hoped but that you do have a couple of good friends.
"Happy Tkday Mark"
"How does it feel"
That friend of yours who always has a shit girlfriend everyone has to put up with, or a crap best mate from school they always ask out with you, or the person who finds the most obnoxious person at a party and exposes everyone to them: i.e. someone who digs up prats.
"I thought she'd be fine at the game, but all she did was talk about her holiday with other girls during extra time. I feel like such a pratdigger".