Yes I vaguely recall having to enter a bunch of 0's in fields (when they were permissive enough to accept that).
As an outsider (and someone who knows nothing about you/your culture) this sounds like "I don't want to accept change" or "noone is going to force stupid codes on to me". So id love to hear the reason!
I live in quite a remote spot, so before, my address was just my name + the general area I live. Thats fine for the postman who knows where I live, but I dont know how other delivery services figured out where I was. Also I'm pretty much at the centroid of 3 towns, and different services would route deliveries via different towns. I had to learn through trial and error to put 'via X' or 'via Y' as my address depending on what service I was using.
Eircode clears all that up.