Do children like to change opinions ?
I guess so. Although personally I don’t know too much about children, it’s true that they change their opinions quite often.
For one thing, they are quite small which means they are exactly at a stage when everything is so new and fresh for them. So it might be the case that today they are still big fans of Teddy bear and tomorrow they would develop a new interest in Hello Kitty.
For another, they are in the process of learning so it’s quite normal for them to change opinions. Something they learned today might be proved wrong tomorrow. Like they may not be into playing piano so much but after trying, they would probably change their idea.
Phrases in use
I guess so 我猜应该如此吧
It’s true that...确实...
For one thing,...for another 一方面，另一方面
be into doing sth. 喜欢做...
Develop a new interest in... 发展一个新的兴趣