1) Can one read his rebbi’s notebook (e.g. cheshbon hanefesh notebook) if it is labeled “private”? The sevara to permit it would be based on the gemara of “torah hi v’lilmod ani tzorich”— in that gemara the rebbi also wanted things to be “private” (perhaps even more so than writing “private”), but we still see that it is allowed to “spy” if it is being done to learn from the rebbi. Is our case also allowed? Please explain.
2) Is that gemara a proof to all similar cases— e.g. recording one’s rebbi without his knowledge/ permission? Why yes/ not?
The idea of “torah hi v’lilmod ani tzorich” is meant to bring out the importance of shimush talmidei chachamim. That when a person is in the surroundings of talmidei chachamim, and he sees how they act in their personal lives, how they eat, talk, deal with people, etc. this will teach the person a lot of the practical side of keeping the torah, and it will teach him a lot. See Abarbenel Avos 6 on tenth kinyan torah- shimuch chachamim). The term is also used extensively regarding a person’s strong will to learn, even if it will mean being in an uncomfortable situation, such as when his teacher is angry or impatient with him, he should still not give up but say “torah hi v’lilmod ani tzorich” ( See Y:D 246-10). However regarding rummaging through a person’s Rebbi’s personal things such as his private kabolos, that he specifically says that are his and he specifically says that he does not allow others to look at it, would be geneiva, and we are not allowed to steal, and go into another persons property in order to learn torah. Unless we know that they allow it (See Avnei Choshen 3- pg. 514). We do find that if a person is specifically makpid on their sefer that we are not allowed to learn in it. Aside from this we have to know that this idea, of looking into a Rebbi’s private things, is not brought in the Rambam, Tur or Shulchan Aruch.
As a side point, I was told by my rabbeim that this hanhaga was only for great talmidei chachamim who were on the correct level, but not for us.