After investing time, energy and money in securing his castle, a lord in the Middle Ages could feel protected within his walls. Enemies would no longer dare to attack.

But large kingdoms fell because they felt safe and rested on their laurels… It's only human! Anybody would reduce their vigilance during times of peace. 

However, a defence system must be constantly maintained if it is to remain effective. Cracks in the perimeter walls have to be repaired, moats have to be cleaned, stocks of arms have to be replenished, etc.

It's exactly the same in a modern business. Investing in your cybersecurity should not give you a false sense of security. Any digital defence system must be maintained, because new IT breaches are discovered every day and can represent gateways for cybercriminals. 

Software developers have understood this, which is why they regularly develop updates and upgrades of their products, in the form of patches, plug-ins, etc.