The actual joke is that they were trying to play dumb/fun nerd computer games. The cool fish basically just told them to count to 1000 instead

for that little bit of program there x is set to 1 and x++ is just another way to say “add one to this number”. The loop runs until x is 1000 thus all the x values when they are “running” the program manually

same but blacksmithing. you can make more tools too