Since getting my first S8 - I don't know for sure - maybe 10 years back - I can absolutely name every night that I tried to go without PAP. Once was probably about at the year to two year mark and I had to get to Vegas for a conference. I was running late, and slap forgot the machine. Worst four nights in memory. Next one was when I went in for a sleep study and they denied me the use of the machine for testing. Good sleep drugs were the only way I could get to any form of (bad) sleep that night. I know ...
So, for that entire period, I have tried sleeping without the machine for five nights. Four and a half, really, as the last three hours of the sleep study were titration.
The thought of doing without causes a level of deep anxiety.