What does this quote mean?

[Accio]

"In a world full of question marks, try to be an exclamation mark!"

 

[Ants]

to me it says that most people are questionable, perhaps neutral, about everything. Being an exclamation mark is standing out and standing up for the things you believe.

 

[shades]

I was going to try and pose an answer, but Ants summed it up the way I would.

 

[mike25]

I suppose a 'question mark' is shaped like a crook ... ? ... or a hook. An exclamation mark is an upside down 'i', so maybe something about going against the ruling orthodoxy - truly being individual - an exclamation mark can be used to convey a wide variety of emotions.
Whoop whoop!