The difference between ...

seeing and noticing.
I have seen this building, quite literally, thousands of times (almost certainly tens of thousands of times). It stands at the top of the street on which I was born, and lived the first 8 years of my life. I have walked, driven, cycled and run along the main road for most of my 56 years, but today, for the first time I actually noticed it.
Funny (and wonderful) how blip makes you take the time to "stand and stare"