If You Can Read This

I spotted a girl wearing a shirt with something printed on the back.

The top line said, 

'IF YOU CAN READ THIS'

She was walking ahead of me and I was curious to know what the rest of her shirt said.

I thought it would say,

'IF YOU CAN READ THIS THEN YOU ARE TOO CLOSE.'

When we were stopped by the pedestrian light, I got a chance to read the rest.

(Clever!)

It said,

'IF YOU CAN READ THIS

I'VE LOST MY BACKPACK.'