We know that making mistakes in mathematics is an inherent attribute of doing mathematics deeply. Yet, making mistakes is at the root of mathematical fear and anxiety for elementary preservice teachers (PSTs). Valuing mistakes in mathematics is an essential part of shifting from deficient views to asset views of mistakes and having better mathematical learning experiences. In two mathematics content courses at different universities, we implemented a project, "My Favorite Conceptual Mistake," as a tool for supporting PSTs in reflecting on conceptual mistakes about mathematics. In this article, we describe the ways that the PSTs reflected on mistakes. The PSTs bravely made mistakes about mistakes, joyfully centered mathematical mistakes, and made connections beyond mathematical mistakes. The PSTs, for example, shared how they made mistakes about their mathematical identities or ideas of mathematical pedagogy. Unpacking the ways that PSTs reflected on mistakes expands what we know about supporting mathematical mistakes and enhances PSTs' experiences with mathematics.