First as a toy he didn't really know truth that's he he needed Jeremy Cricket's company so much. Pinocchio wasn't aware he was actually being captured instead of invited. He had a hard time knowing who was a friend and who was tricking him. He didn't really know the best way to express himself with good manners, he only knew words. So mostly without Jeremy Cricket's help Pinocchio wouldn't have learned how judge consequences as quick. Making decisions cautiously was his biggest lesson.
It's knowing how strong his father's wish was that forced Pinocchio to practice his speech so carefully.