Pablo Garcia-Salaberri contacted me few years ago with a simple request to spend 1 semester at McGill working on fuel cell related problems. I proposed a ‘little’ project for him on the modeling of transport on tomographic images. This ‘little’ project turned into 2 monumental papers which analyzed gas diffusion in wet materials with a whole new level of rigor. I was very happy to learn that Pablo officially earned his PhD today, which included our two papers, but also 4 other exceptional modeling studies which have raised the bar for rigor and thoroughness in fuel cell modeling. Congratulations Pablo, and I hope I have the pleasure of working with you again!