v. To perform a difficult feat, particularly a complex mental task that can't be interrupted for fear of losing the train of thought.
1996
juggling eggs vi. Keeping a lot of state in your head while modifying a program. ‘Don’t bother me now, I’m juggling eggs‘, means that an interrupt is likely to result in the program’s being scrambled. In the classic first-contact SF novel The More in Gods Eye, by Larry Niven and Jerry Poumelle, an alien describes a very difficult task by saying ‘We juggle priceless eggs in variable gravity.’
1995
An addendum here, a few classes filled there and the schedules I had prepared are useless. Making a schedule here is like juggling eggs.
1982 (earliest)
Playing the stock market lately has been as tricky as juggling eggs in the parlor.
You juggled eggs to get me out alive and God knows I'm grateful! But do you expect me to forget that Douglas was behind it?