What does the Gemara mean by including that "Olam HaBa is one of the 3 things that are 'nikneh be-yesurin'? Unlike Eretz Yisrael and Torah, which are acquisitions unto themselves, and thus could (theoretically) be acquired without pain (which the Gemara comes to dispel), Olam HaBa is acquired through Torah and Mitzvos on this world, and thus, le-fum tzaara agrah, it's understood that the more difficult the mitzvah, the greater one's portion in Olam HaBa. In other words, what would I have thought before learning this Gemara, and what additional insight into the nature of Olam HaBa is presented by it?
E Hoffmann, Toronto Canada
At first, I was inclined to say that even if it is obvious that Olam h'Ba is acquired with Yisurin, as you suggest, it would not matter if the Tana added it to a list of three, where the other two are not so obvious.
However, it is not necessary to say this, since the Yisurin regarding Olam ha'Ba, refers to physical suffering, just it does in the other two cases (not to hard work, as you assume). As the Agados Maharsha explains, for a person to earn his full reward, he needs first to suffer in this world, to atone for his sins. And this is something we would not have known if not for Rebbi Shimon bar Yochai's Beraisa.
Kindest regards
Eliezer Chrysler