Decimalisation happened when I was working for Middlewich Urban District Council, in their rates and rent collection department (my first job).
The general consensus was that the 'new money' would be very difficult for the elderly to understand and we were all,amazingly, sent to night school at Crewe College on a six week course to make sure we knew all about the new currency and would thus be able to help all the 'poor old dears' who were expected to get hopelessly confused. We were even set homework in the form of 'sums' to do in our spare time.
In the event nobody got confused at all; even the town's oldest inhabitants, steeped in pounds, shillings and pence since the early years of the century, sailed through it all with no problem at all.
One disappointed man was Mr Bertie Maddock, the rating officer, who was determined to serve the first 'decimal customer' and gave me strict instructions to stand aside when the first ratepayer of the day arrived, so that he could deal with the transaction personally.
It just so happened that he was in the Gents when the first customer arrived and I was able to go down in history as the clerk who did the first ever MUDC transaction in pounds and new pence.
There will probably be a blue plaque on the wall of the council offices eventually.