Me being 6 or 7 at the time...
Was playing it with my dad, and i completely shat myself.
Took us about 1 whole day to do 343 Guilty Spark, because i couldn't play it for more than 30 mins before i started shaking and feeling ill.
But when i saw the elevator that would take us back up i was like " YEY OUT OF THIS HELL HOLE " then the elavator took us down further and i was not happy, and to top it off we get to the bottom and i say
" OH, look, soldiers, they are shooting lets help them, wait...no... OH GREAT THE FLOOD KNOW HOW TO USE GUNS NOW !! "
When we finially finished this level we went to the library and i just had to get used to the fact i knew the flood where going to be everywhere now!
As i played halo 2 i thought the flood where gone, they showed up, even more disgusting and powerfull, saw the gravemind who was a tad freaky and reminded me of Tentacle -blam!-, but i loved the way he spoke, in riddles, utter genius!
By halo 3 i knew the flood would be there, but the little sacks on the walls that pulsated and let out infection forms, that was just gross.
To this present day, i kinda like the flood, they make you think fast, react fast and challange the player! They also give me the side objective to save as many Elites and second prior, as many soldiers as i can!