I'm showing my age now, but I started in computers way before IBM ever produced the first PC that we all now use....
I remember using CP/M machines which had a massize 512Kb of memory, 160Kb 5.25" floppy disks, and 5Mb of hard drive space - VERY advanced at the time, but now it just sounds silly.... I recall changing from CP/M to MsDos and it took an age to get used to silly changes, even though MsDOS was derived from CP/M. For example, the "Copy" command was reversed - Instead of Copy <to> <from> as you did in CP/M, allof a sudden it became Copy <from> <to>..... Way before graphical interfaces had even been thought of!!
Then came the multitude of Hard drive format - we had MFM, RLL, ESDI, SCSI etc etc.... I remember buying two 330Mb ESDI hard drives which cost me almost £1500!! And that was 20 years ago!
Same thing happend with modems, my first was a split baud rate 300/75bps unit - Yes BITS per second, not MEGABITS! Eventually the 14K4 modem came out and I spent £800 buying one - It was obsolete within 6 months!
If I'd saved all the money I've spent on computers over the years I could have bought a house!!! And no, I'm NOT kidding!