I think Garriot said originally he stepped out of the fire instinctively. Then remembered "Wait I'm invincible I can stand in fire." Then proceeded to stand in the fire and die.
Which is kinda funny as it's become a meme about WoW players standing in fire and dying when they couldn't just moved. (To much frustration to healers)
That’s mostly just poor game design as players don’t worry about standing in fire when leveling up. MMO’s tend to add such arbitrary new gameplay mechanics in raids and nowhere else. Then everyone gets annoyed because players can only really practice in raids.
In UO standing in fire walls was a method people used to skill up. UO was skill based, not level based. And you gained skill points by doing those actions. A good way to have a group build up spell resistance was to cast fire field, everyone stands in the fire, and have someone cast heals. Casting the field and the heals also improved casting abilities
Which is kinda funny as it's become a meme about WoW players standing in fire and dying when they couldn't just moved. (To much frustration to healers)
https://wowpedia.fandom.com/wiki/Stay_out_of_the_fire