A container assembly maximizes lid-to-container retention or prevents inadvertent removal of a lid from a container, and includes a container and a lid. The container includes an upper rim and a container wall. The container wall includes a seam and a primary indentation. The indentation traverses the seam at an inner container surface in parallel relation to the rim. The lid comprising a rim-receiving groove, a lid wall, and a wall-to-groove resilient portion. The resilient portion extends intermediate the lid wall and the rim-receiving groove and is resiliently actuable intermediate a relaxed configuration and an actuated configuration. The resilient portion has at least one indentation-engaging portion. The rim-receiving groove receives the upper container rim, and the indentation-engaging portion engages indentation when in the actuated configuration. The rim-receiving groove and the indentation-engaging portion together lock the container lid to the container when in the actuated configuration for cooperatively maximizing lid-to-container retention.