My earliest "gnarly bug" experience was that the "set flag" operations in ZZT are limited to 8 flags, but it doesn't throw an error if you exceed that limit; it just wraps to the zeroth flag. It took me a full year to figure it out as a ten-year old.
warms my heart to see this so high. that summer I was 10 and discovered ZZT and the surprirsingly robust editor and language was really where it all began for me tech-wise. and I was just thinking about it two days ago
> It took me a full year to figure it out as a two-year old.
o_O
Edit: i see you corrected it now, but with hn you never know..