"Knight in Shining Armour" what's that supposed to mean?

My Knight in Shining Armour, wears T-shirts and denim jeans. 

He might not fight off dragons, or have a pet reindeer

But the reason he's my Prince Charming, is still pretty clear. 

He'll hold me when I'm ill, or just to show me love

And his blue eyes sparkle like all the stars above. 

He always making jokes, and sticking up for me

My Knight in Shining Armour is also trustworthy. 

To end this tasteful boast that could go on for days

Just letting you know that my Prince Charming... I will never trade. 

So forget that universal term "Knight in Shining Armour"

When a prince can wear far more.