The same thing can be seen on some MIUI device that i used before. Need to quickly press the recovery keys combination to enter TWRP. Entering recovery command from terminal would directly boot into OS.

Not to mention if you suddenly developed amnesia or dementia

My 1st android device would be 2nd hand xperia x10, i remembered installing cyanogenmod 7 on it and learning about rooting through it

Hey i too used to have the same device, altough not the 1st one