We would manage without them just like we did before we had them, it just wouldn't be so easy. I find my pc invaluable these days for shopping, banking, contacting friends/family etc. but I remember 25 years ago when computers were only just being introduced in offices, let alone homes.
My husband was a hardware/software engineer/consultant and he kept offering to give me a short course on computing. I was quite sure I'd never cope and kept putting him off. A couple of years later the Civil Service started to go computerised and I had no choice. Now, nearly everyone has one at home and tiny children use them with ease, it makes you wonder what we'll have in another 25 years. (In my case, probably a zimmer!

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