My ZX81 self-build kit was a present from my parents when I was 14.
It had been packed in such a way that the pins of a couple of the ICs had punched through the membrane keyboard, rendering it useless - it took weeks, and many irate phone calls by my mother, to get a replacement.
Eventually it did all work though, and I spent many a happy/frustrated hour tinkering - I built it into an old Linotype Paul case with a full size keyboard, inverted video output (white text on black background) and a ram expansion on a ribbon cable (so no wobble).
40 years later and I'm still a serial tinkerer and coder.
A few years ago a school friend got me an autograph from Sir Clive with an apology for the damaged keyboard!