The thing I can never work out is why, when those phones were ubiquitous, did they make the UK emergency service number 999, which by my reckoning is the 4th most time consuming 3 digit number you can dial?
Why not make it 111?
Because 111 could be dialed too easy by mistake
Time for an anecdote from the old days:
On phones of the age of mine you could dial the number of the local newspaper, 11 11 11, merely by knocking on the chassis six times
ETA: The words "HJÆLP - DREJ 000" prominently displayed on my phone, mean "HELP - DIAL 000" -the winner of the category of most time consuming three-digit numbers to dial on a rotary Phone... nope, has to be capitalised: Most Time Consuming Three-digit Number to Dial on a Rotary Telephone! -yeah, much better that way