After the PCS master, I did a PhD on the modelling of railway traffic in dense zones, with a CIFRE contract with SNCF. Now I am a research engineer at Withings. I recommend the PCS master to the students who wish to complete their scientific background and unveil an entire section of modern physics. In between mathematical formalism and physical phenomena, the PCS master is not only an invitation to curiosity and a quality training towards research, but also a hidden door to the world around you. A curling hair? A boiling kettle? A snowflake? The spreading of an epidemic? The pattern of a sea shell, a zebra, a giraffe? Something is certain: if you get involved in this master you won’t see physics as before!