No, please. I bought a "ticket" that wasn't actually a ticket (had to use the red box to "convert" it?) for a train and got an earful. Also walked into a Rewe with a bottle of water and the cashier was really displeased.
In the UK and some other EU countries, you'd just pay on the spot (either the fine or the ticket price). Some things aren't worth that much policing.
I suspect you bought a ticket that can be made active any time, so you could buy it in advance if you wanted. To make the ticket "active" you have to stamp it using the pillar thing with the automatic date stamp at the station. Common mistake, but understandable you got an earful because you might as well be pretending you didn't know how things worked and are actually just riding again and again using the same pretend-ticket.
Similar with bringing a bottle of a brand that the store sells into the store - how are they supposed to know if you brought it in or if you just took it in the store and opened it there on the way to the cash register? (which, by the way, is not super uncommon either and generally tolerated)
German police are not allowed to collect fines on the spot, it's a corruption prevention measure.
In the UK and some other EU countries, you'd just pay on the spot (either the fine or the ticket price). Some things aren't worth that much policing.