Rabbi Shimon Bar Yohai was a Tanna. A Tanna was a Rabbi Mentioned in a Mishna – which explains the laws of the Torah. The Mishna & the Gemara – the explanation of the Mishna – Together is called the Talmud.
When G-d gave the Torah to the Jews – he gave the written Torah (the 5 Books of Moses) and Oral Torah. The Oral Torah explains the Written Torah.
When it was being forgotten, Rabbi Yehuda Hanasi decided to commit the Oral Torah to writing – this is called the Talmud.
Any Tanna – Mishna Rabbi or Amora – Rabbi from Gemara – was so great that they were able to bring the Dead back to life. Rabbi Shimon was a Tanna – Student of the Great Rabbi Akiva.
Lag Ba’Omer – the 33rd Day of the Counting of the Omer – is the Hillula / Yartzeit of Rabbi Shimon Bar Yohai – when He died.
He ordered that people celebrate the day of his death. Usually, death is synonymous with crying and sadness. So why do we celebrate lag Ba’Omer?
Rabbi Shimon ran away from the Romans. He hid in a cave in Meron for 12 years with his son – R. Elazar. During these 12 years – they ate carobs for food and drank water. They were involved in Torah study day and night.
He reached such a high level of holiness – that he was able to reveal great secrets from the Torah. He reached His potential in life. We rejoice his reaching of potential.
There is a question – why do people cry when someone dies?
Apparently – one cries because he will miss the other person. But it is also possible that the remaining relative realizes that the person didn’t reach their potential in life and that’s what causes him or her sadness.
Rabbi Shimon – did not waste his potential. He reached his potential and purpose in life.