Riddle of the week

Someone came to visit Motty's class this morning and ask if he can stay for the day. The boys giggled, he then asked "who was a big tzaddik that went to learn alef beis in cheder with boys your age even if he was much older than them?" he was of course referring to Rebbi Akiva, not thinking they didn't learn the story yet. Motty piped up "I know Reb Efraim!"