keen as a bean

Etymology
Chosen for the rhyme.

Adjective

 * 1)  Very keen; enthusiastic; eager.
 * 2) * 2018 Alasdair Duncan, Here’s How To Improve Your Pitiful Uber Rating From Someone Who Did It Pedestrian, 17 September 2018. Accessed 4 May 2019.
 * On my afternoon trip home, I struck a driver who seemed keen as a bean to get me to mash that five star rating – his Mitsubishi Outlander was stocked with mints and bottled water and he offered them all to me and even asked if I wanted to make any extra stops on the way home.