I must be the only person on the planet who didn't realize today was tax day

The boy and I left early today to get big sister from school, thinking a quick stop at the post office would fit right in. Well...I live closest to the main post office of a city nearing a population of one million people who didn't want to send their tax forms until the very last minute.
Once I finally got into the parking lot, the boy wouldn't hear of just cruising thru. We fought the moving cars, got inside, and waited about 20 minutes for the automated machine to get postage. The line for a clerk went out the other door.
We were late picking up big sister, but, at least it wasn't raining--only cloudy and cool.
The good news is: abdconsultant has a package on the way. 2 business days!
I hope no one else had the memory lapse I had...