Re: 400 Gb on your little fingernail....
5mb? Tha were lucky!
First computer I used was a Varian V70 which used paper tape. That had enough core (and I mean "core" as in ferrite ring memory) for each of the 8 users (each sat at an ASR33 teletype) nearly 4k of storage - happy days.
The next one was an IBM 360 which used punched cards, well it would if they weren't all nicked to use as roaches.
First real hard drive was a ST157a - 57M unformatted, about 44M formatted.
Now these however could be fun, 9 in RAID 5 to make a smaller than matchbox sized 3TB array with redundancies. about 100 of those could be crammed into a 1U rack, that's a lot of storage in a small space, probably glowing red-hot due to heat dissipation problems but that's part of the fun.