So you think the whole family forgot about Jesus until they got home? This sounds like an episode from Everybody Loves Raymond.
Does the text say they were home?
How ludicrous.
Do you think Jesus' parents thought He was irresponsible and untrustworthy that at age 12 He couldn't have been left to spend time with His friends and be trusted to stay with the group?
In that culture, he was on the border of being called a man. He had better have been responsible and mature.
I would hazard a guess that 12 year olds in those days were a tad more mature then they are today.