The DVD and CD only lasts about 5 to 10 years, and if exposed to the sunlight, much less time. The vynil record and VCR and cassette tapes last the longest, but the machines to play them have been made intentionally obsolete, so that we will forget our past, by those who control us. The digital formats on USB and SIM cards can become corrupted and lost their data. Books are the best way to retain memories- Books and photographs. only these last many centuries, not just mere decades, and they require no machine to view. I too, repair electronics and most of the things I have repaired have been discarded and no longer exist. We live in a society where things are disposed of when they fail to function, out appliances, our phones, our relationships- all just become faded memories of the past and then completely forgotten after we die. I keep working televisions and VCRs and phonographs, and old computers of different operating systems in a safe place in my house, incase there happens to be a wise one who should encounter them after I die, and realize these can be used to view things nothing digital can show. But when I die, the people will probably just throw away everything, not understanding they are blinding themselves to visions of their ancestors. Their short term greed for property and land will make them poor in their early future, as they have no future by their own design. Just a repeating daily struggle for existance, that they cannot overcome.