Exploring dungeons isn't easy, what with all the rolling boulder traps.  Some creatures even enjoy being hit with a +2 bullwhip.  Not snakes, though.  "The pit viper falls into a pit!  How pitiful.  Isn't that the pits?"

If you need to hide from enemies in a bookstore, always remember to pick up a book and look like you're thinking about buying it.  Stay in there for as long as you need to.  The shopkeeper will keep those ruffians away from his customer.

If you have something you want to get rid of, find someone who will take it from you.  But first make sure that you've nothing else left for them to take.

I and Celeborn the elf-lord went to our reward with 4798200 points and 115592 pieces of gold, after 81116 moves.  I was level 29 with a maximum of 593 hit points when I ascended.

I never thought of that! I always knew that it was a big big mistake to attack a shopkeeper when playing nethack, but I hadn’t considered that shopkeepers could take care of unwanted nasties for you.
It's simpler than that. If you are holding merch, he blocks the door!