An Etymological Dictionary of the German Language/vergessen
vergessen, vb., ‘to forget,’ from the equiv. MidHG. vergëȥȥen, OHG. firgëȥȥan, str. vb.; a West Teut. word; comp. Du. vergeten, AS. forgitan, E. to forget. Also the equiv. OHG. irgëzzan, MidHG. ergëȥȥen. The compound verb is the relic of a strong verbal root get, ‘to reach, attain,’ whence E. to get; comp. Goth. bigitan, ‘to find, OIc. ‘to reach, attain,’ In non-Teut., Lat. prae-hendere, ‘to group,’ Gr. χανδάνω (Aryan root ghed, ghend), are connected with the root get. Hence vergessen means lit. ‘to get beyond one's reach, lose possession of.’ —