I can’t stress this enough: if it’s digital and it matters, make a backup. If it matters a lot, make a backup of the backup and then backup those backups.
I’ve been doing a lot of moving between computers lately and somehow a bunch of videos didn’t transfer across. Those videos just happened to be of my daughter’s first months.
Luckily I have backups on disc, but I couldn’t read the discs: none of the computers I have here have DVD drives, and even if they did I wouldn’t be able to use them: the recordings were on mini-DVDs, which slot-loading computers can’t play. If it weren’t for my brother’s timely loan of a portable DVD reader I’d be in deep trouble.