Lovelines (aka The Eddie) - S6-E19
Character mistake: In the scene when Dr. Drew has Joey and Eddie on stage, they are arguing and Joey says that Eddie moved away and dumped her twice. Actually, he only dumped her once, when he moved out of his apartment and back home with his parents. The 2nd time that Joey is referring to is when Eddie moved to California for the writing workshop, which SHE helped and encouraged him to do. So he did not dump her 2 times; she basically pushed for him to leave the 2nd time, yet she acts as though this situation never occurred.
Answer: It's only explained once in the series. Jack says to Andie "I tried to start kindergarten without you", meaning Andie was smart enough to start school early.