explain this ?/

[MCMARK]

so ive been back to the gym for a few months after a neck injury from motox..im back to par and once again seemed to hit the platue that i always hit when i get back to around 200lbs ..i have made a few life changes like drink less 1 big day and 1 small day a week instead of a few days aweek..also started eating a little better ,like oatmeal for break with whey powder,flax seed ect.but ive been doing this eating better for about a month.
then yesterday i go to the gym and do the same leg route i allways do..i start with leg press for 400lbs and do 15+ to warm up
then i add 200 more and do 10+ for asnother warmer
now i have 800lbs which i max out at for 3 sets 0f 6-8 ussally but on the first set i do 10+ and it seems way to light so i need to up the weight
i put on 900lbs and once agan do a set that hits 8 reps..wat da fuc.. i never do this weight
so i put a total 950lbs on call my buddy over to spot just to be carefull and do a set of 7 easy
i coulda gone way heavier but was a little reluctant since this isnt a weight i ussally do,in fact its 150lbs heavier than ussual
i wake up this morning waiting for the leg pain to come but it still hasnt
only other difference i can think of is that now i snack before bed when before i didnt and i use vit. pills
explain this one willlya

[Hypertrophy]

It could be 1,839,439,509,435,430,490 different things???????