labour of love idiom
C2 出于爱好而做的困难工作;甘愿做的事
a piece of hard work that you do because you enjoy it and not because you will receive money or praise for it, or because you need to do it
He's always working on his car - it's a labour of love. 他总是在鼓捣他的汽车——那是他的爱好。