Departing Oakland for Redding, California, NorCal Departure handed me off to Oakland Center. I changed frequencies but attended to some other issues and couldn't remember if I'd checked in:
"Oakland Center, Skyhawk XXXXX, six thousand. I can't remember if we actually checked in or if I just thought about it."
"XXXXX, roger. No, you didn't check in but it's the thought that counts."