1. I don't keep track of PCs' kit and abilities. Just because 29 hit last time doesn't mean they can't do some whack-ass thing this time.
2. It's fun to ask

LOL, you think I have PC ACs memorized? I asked if a 29 hit because three times a day you can activate the ring of wizardly bullshit and I need to know if I’m rolling 12d6 or not

Look, if you can be excited about big numbers your DM can be too. Also having someone capable of hitting a 29 tells you how seriously you need to take the encounter