The dynamic interplay between cholesterol, asymmetrically (at physiological condition) or symmetrically (hallmark of aging) distributed in membrane, and β amyloid peptides is investigated by a computational approach. The drawn overall picture, starting from the very appearance of β amyloid peptides and going through their self-assembling into potentially toxic oligomeric species, reinforces some of the experimental and theoretical shots recently reported in literature, while new important molecular hints on the physiological role played by the β amyloid peptide are proposed. The so dreaded formation of amyloid pores selective for the passage of calcium ions could in fact explain their physiological concomitant recruitment in the regulation of synaptic plasticity.