(ERAU-related comment)
There was a day that we were something like 723, there was a SouthernJets 1223 and an Airliner 723.
Oftentimes I'll revert to "seven two three" like we use internationally for clarity, but it's a super easy mistake to make when you're not super careful.
My callsign-related screw-ups are usually related to something like this (they have decreased in frequency as generally I'm not doing nonsense like that anymore, but by the end of this particular day, who was who was a tenuous proposition):
Or having an "alternative" callsign (Buzzsaw 5392 [d/b/a Buzzsaw 598X]). Individual digits get read out sl-ow-ly, almost to the point of gumming up the works.
Could happen to you. No one is immune to error.
Yeah, I didn't like what I listened to this morning. BOTH the clearance acknowledgment, AND the subsequent readback were stepped upon. I do like how places like Vegas have discrete tower frequencies for each set of intersecting runways, and a box that tells each controller who "owns" the intersection, but this wasn't ATC's fault in the least.
Slow down!
We generally hear what we want to hear, and when you're
holding in position lined up and waiting, that's "cleared for takeoff." I can see it happening in San Francisco, with traffic lined up on runways 1, and traffic lined up on one of the 28s as well. Case in point, not related to runways: I
thought I was cleared direct to the Bonham VOR one fine morning all the way from Greensville (landing DFW). I don't remember the name of the fix, but it was something that was very phonetically similar to the name of the VOR. "Hey Beagle 3155, where ya goin'?"
On a somewhat germane note, if you check on ONLY with the numerical part of your call sign, we will have a problem at some point. (That was another wart from the Beagle days, as it turns out there was an Airline Canada airplane on the frequency with the same number...)