Yeah, totally agree.
And the trouble with the seemingly impressive undercard at Glastonbury is that the stages are massive distances apart so you can't realistically see who you want to see. And if it's muddy even more so!
Treat it like a ticket sale and you'll be fine haha.
I'm sure there's around 6000 CV tickets and combine that with how many of us are old enough to need a bed and proper sleep means they usually sell out very fast. Everyone manages to get one on the sale day it seems!