What is the difference between calling .first and .first()? So here's something I've never been able to figure out about Twig. Does it make a difference if you include the parenthesis for functions or not?

In other words, what is the difference – if any – between calling

craft.entries.first


and

craft.entries.first()


?
On a more philosophical note; Put yourself in the shoes of first(). It's a method, doing an important job in the Craft eco-system. It prides itself on returning the most important and relevant data in an efficient and unencumbered way. Serving up entry after entry, asset after asset, 24 hours a day, all week, all year. Never complaining, never getting any praise.

And you want to treat it like a simple property? As a dumb, brainless reference to some data that some other method created? How do you think that makes first() feel? How would you feel if someone treated you as property? 

I know you're a good person with a big heart, Mats. I'm sure you will do the right thing and treat first() with the respect it deserves, even though it means that you'll have to write a few more characters a day.