Is psychiatric and pediatric need to be good at science?

Pursue it. Yes it is a lot of science and yes there is a ton of memorization. However, it is much easier and more fun when you are doing it with something that you are really interested in. Besides if you decide that you do not like it you can always stop and switch to something else. It it better to try then to never try and regret it. So go for it! Also talking to people that are going into that field will help you decide also. They have the first hand knowledge of what to expect. But either way try it so you can make your own decision don't let others discourage you or scare you away from it because it is a lot of fun to learn about that stuff!!