The most of bee nursing is preventive.
A beginner must learn first tha natural cycle of the hive during a year. Gradually he learnso see
what is going on and what bees are going top do. That in mind the beekeeper try to lead the bees' instincts according his mind.
Hives act in different way. That hives more knowledge what is ahead. with one or two hives the learning is slow.
But bees stand many kind of beekeepers. But there are allways the limit. Some hives try to vanish because life with the beekeeper is impossible
Then you wonder why bees vanished.