Back in the day, I completed this zeventyfazillion times. I could do it with my eyes closed. I could do it upside down in a bucket of water. I could do it by shouting instructions over the phone to someone else holding the controller.
Now? I can’t get from 8-1 to 8-4 without losing at least two lives, can’t get past the water bit on 8-4 at all, and am generally just crap at it.
Clearly, Nintendo have hardified it since the NES era. FACT.
I’ve left the game saved at the beginning of 8-4 as Super Mario and with two lives remaining. No doubt when I come to continue, I’ll fall in the lava pit immediately to my right twice in quick succession.