Are you old enough to remember DOS as an everyday thing?
Yes, my very first computer had only DOS.
If so, what DOS commands do you know/remember?
cd, md, del, dir, move, copy, cls, echo, format. Don't think I can remember all their attributes.
Did you have any DOS games that you still have and play, or can't play any more because they won't run under your current OS or else run too fast now? I have a few saved somewhere on CD, but none that I currently play.
Could you write a batch file, right now, if you had to?
Yes, they are still very useful.
Is there anything you prefer about command-line operating systems as opposed to GUIs?
Not really, in my work GUIs are more effective, but command-line still have some uses.