I can remember and still have a scientific slide rule in my desk. I used them when taking some engineering classes in the early '70s.
While I was stationed at NAS Kingsville, TX, Sears had an advertising mistake and I took advantage of it and bought my first HP scientific slide rule calculator. Even with the advertising mistake it was over $100 which was a chunk of change for an E-6 with a wife and 3 kids at the time. It would take some work to remember reverse polar notation....
Now most people don't know what a slide rule is for ........and calculators with a lot more capability are a lot cheaper!
And this deaf guy is sitting here listening to music CDs via a set of head phones and a cochlear implant. Is my hearing perfect? No! But every night when I remove my hardware prior to going to bed, I am reminded what my 17 months of being deaf was like.
We live in a wondrous time.