leave footprints in (something)

To have a significant or lasting impact on someone or something. A possessive adjective can be used between "leave" and "footprints." It's very common for a first love to leave footprints in your heart. You only get one first love, so you'll never forget that person. Mrs. Smith was one of the most beloved teachers here before she retired. She certainly left her footprints in the St. Pius community.