A proverb meaning perseverance pays off; if you stick with something for three years you'll get results.
新しい仕事は大変だが、石の上にも三年だと思って続けるつもりだ。
The new job is hard, but I plan to keep at it — perseverance pays off.
ピアノが上手くなりたいなら、石の上にも三年、毎日練習しなさい。
If you want to get good at piano, practice every day — perseverance is key.
親によく『石の上にも三年』と言われて育った。
I was raised often being told 'stick with it for three years.'