I think that some objectivity is fine. I leave the house without my wallet and license sometimes and have missed a sticker by a few days due to forgetting or circumstance. I've been let through with a warning as I'm known and not a dodger just forgot. If I did that elsewhere where not known or overseas I expect a ticket. If I got a ticket here fine I messed up but the aim is to catch those that are consciously dodging the license stickers insurance etc so some latitude is surely fine