牛に引かれて善光寺参り
Meanings
1
unexpected good fortune through another's invitation
Proverb meaning that one ends up doing something good or beneficial by chance, often through being led or invited by someone else. Literally 'being pulled to Zenkoji temple by a cow', based on a folk tale where a woman was dragged there by a cow and ended up finding faith.
The seminar I went to because a friend invited me turned out to be very useful. It was truly a case of being led to something good by chance.