Sourdough flavor..

I've been hesitant to bring this up because I thought maybe it was my imagination, but I think not.
My sourdough loaves become more sour or tangier after 2-3 days. I find on the first day a very mild sour, but after a few days it's just the way I love it. There is a definite increase in flavor. Is it just me or does anyone else experience this change ?