Hydrogen depleted environments have been considered an essential requirement for the efficient formation of fullerene molecules in circumstellar/interstellar environments. In particular, the hydrogen-poor, helium-rich, and carbon-rich character of the gas around R Coronae Borealis (RCB) stars has been suggested to be a promising site for the efficient formation of these complex molecules. These suggestions are not supported by the Spitzer Space Telescope observations presented here, showing that infrared transitions of fullerenes are seen together with polycyclic aromatic hydrocarbon (PAH) features in H-containing Planetary Nebulae (PNe) and the two least H-deficient (hydrogen deficiency of only ~10-100) RCB stars. Present observations of fullerenes in PNe and RCB stars suggest that both PAHs and fullerenes may be formed by the photochemical processing of hydrogenated amorphous carbon (HAC), although other chemical routes cannot be discarded. We present accurate C60 and C70 abundances and C70/C60 ratios by using the most recent laboratory data on C60 and C70 fullerenes, which give us essential information about the conditions and the chemical route for fullerene formation in H-rich circumstellar/interstellar environments.