I've had my share.
Not long after we were wed my wife's firm, a major US defence contractor, decided their London office needed a PC so they spent £5,000 on an original IBM PC with twin floppies ( an optional extra), monochrome monitor, a Brother Twinwriter, a modem possibly 300 Baud and the software.
It took a while for BT to install the data line but they did, and She Who Must Be obeyed came under pressure to hook her computer up to use their in house e-mail running on a 1950's redundant IBM mainframe that only understood capital letters.
By the way I am a structural engineer. Concrete steel bricks etc.
Any way the day came and I got the phone call "I cant connect to the leased line" so I asked have you connected all the cables?
Phone socket to modem - yes
Mains to modem -yes
Modem to PC - What cable there isn't one. Why would I need one?
Phone call to supplier "oops we forgot that £40 for parallel cable."
My wife hit the roof and they agreed to supply one in place of some accessory to the Twinwriter ( I think the sheet splitter) that was still on back order.
The funny thing is she only called me after her boss a qualified electronics engineer flogging missiles and radars failed to diagnose the problem.