Learn and Teach

Ars longa, vita brevis (Hippocrates, ancient Greek physician)
Life is short, the art [of medicine] is long.

Usus est magister optimus
Experience is the best teacher.

Solvitur ambulando
It is solved by walking.

Longum iter est per praecepta, breve et efficax per exempla (Lucius Annaeus Seneca, a.k.a Seneca the Younger)

Teaching by precept is a long road, but short and beneficial is the way by example.

Experientia docet (Tacitus)
Experience teaches.