Suddenly I feel like this one is about grad school.
(Ishi no ue ni mo sannen; “Three years, even on top of a rock”)
With perseverance, one can overcome hard times and achieve one’s goals. A saying about the importance of patience and endurance. Before you start getting the wrong impression, let me note that the image being referred to is not simply enduring the hardness of a rock as one’s seat. The full-length original saying refers to sitting on a cold stone, and how the cold stone will eventually warm up if one sits on it for long enough! Naturally, one should not take the number at face value: the span mentioned is simply an example of a relatively long passage of time rather than a prescription for exactly three years of stone-sitting.
The noun 石 (ishi) is a rock or stone, and the noun 上 (ue) is equivalent to the English prepositions “above” or “up.” These are connected by our old friend the associative particle の (no) to form a noun phrase. Next is the particle に (ni), used as a positional and probably best rendered as “on.” The particle も (mo), often translated as “also,” is taking on an emphatic function here: “even a (cold) stone.” Finally we have number and noun 三年 (san.nen), “three years.”
The full version adds 居れば暖まる (ireba atatamaru), “if one sits, it/one will warm (up).” There are two interesting things here for the language-learner to pay attention to. First, while in modern Japanese 居る is simply the verb “to be” for animate beings, equivalent to ある for inanimate ones, classically it literally meant “to sit,” “to be seated,” thus referring specifically to sitting on a stone rather than simply being atop it.
Second, the kanji 暖 usually refers to a feeling of warmth, whereas warmth in an object or substance is represented by 温. This doesn’t seem to be a factor in this case, though… especially since 三年居れば温まる is a valid alternative to the saying. It’s possible that 暖 was chosen simply because 温 can also refer to an unpleasant lukewarm quality, but this is just idle speculation on my part.
Another variant kotowaza has us persevering 茨の中にも (ibara no naka ni mo), “even in the middle of a thorn-bush.”
(“Natsuyasumi no aida demo, ishi no ue ni mo sannen no kimochi de mainichi sanjikan jishuu shiteiru gakuseitachi ni kandou shita.”)
[“We were impressed by the students who, believing that perseverance is the key to success, studied on their own for three hours each day even during summer vacation.”]