Happy Apple

In the Lord of the Rings movies, Merry and Pippin were as youthful idiots.
Pippin especially, but Merry as well. As I recall, in the books Pippin
*was* a youthful idiot, but Merry was more of a middle-aged, responsible,
non-idiot hobbit.

It's been a while since I've read the books (around the time the movies
were released), but am I remembering correctly about the books? Was Merry
an idiot or a non-idiot?

Thanks,
Wayne

PS. Normally, I'd look this up myself rather than bothering people about
it. Jo has decided our house needs sorting and organizing and all. Our
books are in an uproar and nothing is where it should be, nor will I be
able to find anything until this task is mostly done. Maybe next year.