Grains, grains, and grains... We are surrounded by grains, starting from our house to industries to nature. Typical examples are food grains, flour, sand, mineral ores, catalyst pellets, pharmaceutical powders, etc.  They are the second-most handled material after water and play a pivotal role in shaping the earth's landscape. Their fascinating yet complex mechanical behavior has motivated scientists like Osborne Reynolds and P.-G. de Gennes to dive into the exploration. Still, this field is far from being developed with several open questions, which we address, employing experiments and numerical simulations to improve handling of these materials.