My first job after graduation was in land management, and part of it was to monitor the nest boxes for occupancy. During breeding season, I'd go and check them every two weeks ish, take photos, and record species and numbers of chicks. Mostly, this meant blue tits.
Anyway, early on, I do my rounds one day and get back to my office to record the findings. As I'm looking at one of the photos, I think to myself "Hang on. These look different from the others. They have black heads, not blue, and I think maybe they are bigger. Perhaps these are great tits?"
But of course! As they were still moulting, I wasn't sure; and so, with the wisdom of the terminally stupid, I confidently opened up Google, went to an image search, and there on my work computer in my office in my brand new job, I typed in "great tit chicks."
The results I got were not what I expected. But. Should have been.
I had to IMMEDIATELY go and fess up to my new boss and be like HEY I don't know if you monitor our internet use at all but uuuhhhhhh I can explain. Fortunately she just about pissed a kidney laughing, so it was okay.
(They were indeed great tits)