Its interesting, how we can recognize who never had any Amiga before!
The Disk Drive Amiga "Click" its part of the hardware idiosyncrasy.
Yeah, its the only Computer tell to you "i am alive!".
For me any Amiga without Disk Drive "click" sound, its like death Amiga.
In 1985, that came with Amiga. Later with CDROM Drives in PC Computers, start to use something similar to that in Amiga. If you insert a CD in any CDROM start to read a CD, you know like the Amiga`s Disk Drive.
Anyway, The Flicker in high resolution, the DD "Click" sound, " Guru Meditation", and other things are Classic Amiga Features, and came with all the Package Amiga is.