R&D for a future muon collider is a topic of growing interest in the high-energy physics community. In this talk I will illustrate how even theorists can contribute, by focusing on a specific signature: forward muons. I will explain why these pose a unique challenge for muon collider R&D, and argue that there is a strong physics case to plan for a dedicated muon detector in the forward region. I will also discuss the capabilities such detector would need to possess, to enhance the sensitivity to beyond-the-Standard Model physics.