Does it ring a bell?

Opppps! 

It's been a while... 

We have to catch up!

This is an idiom that I use very often in class, so I assume hope you won't have any problems guessing its meaning...

Let's start with several examples:

The name of the company rang a bell but I couldn't remember where I had heard it before

No, I'm sorry, that description doesn't ring any bells with me

That rings a bell

And now let's check the meaning!