My "raison d'être" in science is the application of innovative high-​pressure high-​temperature experiments to geological problems. My earlier career was centered on metamorphic reactions and simple system phase equilibria, their thermodynamic analysis and some crystallography, mostly targeted at subduction zones. Nowadays, I am more interested in magmatic systems and the related mass transfer. Partial melting in presence of volatiles shapes our planet, requiring us to understand primary and parental melts in terms of major elements, traces and isotopes. I firmly believe that no magmatic process can ever be clarified without understanding major element behavior and hence continue to take great pleasure in developing phase diagrams and solubility models. Recent and ongoing topics are on kimberlites and alkaline melts in the deep mantle; carbonatites; liquid immiscibility and related trace element partitioning; volatiles during core formation; redox processes in the mantle; crystal settling, compaction and melt extraction; and experimental isotope fractionation.