To get irritated at others writing comments in books?

I hate seeing writing in library books and cannot write in books even if they are my own. I have just finished an OU English Literature module and used post-its to mark points, I could not write in the books. After four years with the OU, this was the first year I let myself write in the module text books (which are mine to keep) but only in pencil.

Newquay, why do you correct grammar mistakes? IMO they are annoying, but less annoying than seeing someone's writing in a library book!

It is annoying. It pulls you out of the story and reminds you that it is words on a page. Not that you forget that but it breaks the mood of the book.
Philip Larkin used to write in books including library books and the scribbles are said to give insight into his character. I am not sure that that can be applied to many people though.

Yes it is irritating and disrespectful of the wonderful services the libraries provide for free.

When you return the book show the librarian

I DO correct grammar mistakes in books-shock, horror-but would never deface a book otherwise. As OP says though it's good to see a book well used and therefore presumably well loved.

The only books I've felt the need to write in, or underline anything, was when they were my own and I was writing essays on them for an OU course. There would be a stack of post-it notes to mark the places, too.
With hefty reads like Middlemarch, I don't know how I'd have managed otherwise.
I would never make any mark in a book that wasn't my own and unless writing essays on them, have never felt the need.

Grandma 70s -I did too. All my Famous Five books etc had coloured in pictures. I can't see what's wrong with it if it's your own book. I would never write in or spoil in any way a library book or a book I borrow from someone though.
To me a book is for reading not wrapping in cotton wool. The more dog eared a book the more it's been read and loved. Like a battered old teddy!

I don’t mind the occasional pencilled comment or correction in books, unless the book is a beautiful edition. There are books and books.

As a child I coloured in the pictures in my own books if I wanted to. Nobody policed my reading. I wouldn't have done it in a library book.

No you are most definitely not being unreasonable Doodle like other posters I was brought up to respect books and hate it when readers deface them.
As purpledaffodil said its vandalism.

I agree, Doodle. I read lots of library books and regard people who write comments in them as vandals!
Books are sacred to me, to be loved and cherished, even when I don't actually own them.
So, no, you are not being at all unreasonable.

Absolute vandalism! I wouldn’t even comment in my own books, let alone a library volume.
Many years ago I was a school librarian and spent many happy hours with sellotape pulling off badly spelled rude words written in biro. ( My particular favourite was “buger of”.At least the pencil ones could be rubbed out?

Oh that really gets me, I was brought up to respect books, I was bought colouring books, and annuals for children when young, and was allowed to colour as appropriate, but nowhere else. My school was very hot on it, I remember once I was called to the front of the class because my teacher thought I was writing in a text book, I wasn’t, I was tracing a diagram, yes it was homework I should have done for the next lesson buts that’s not the point !, the teacher really told me off and couldn’t tell what I was really doing. I was always given the old text books then until I could prove I respected them, couldn’t do that now a days, poor little darling might cry.

Really annoying, read one library book that was censored. Every expletive or mild bad language was tipexed out. Plus whole passages were deleted with a black market pen.
Reportedly to the librarian who tried to see who had it recently.
If the person doesn't like a book the close it and don't read it !

Oh, don't get me going on this!!! It drives me up the wall!!!

Even on pages with no pencil comments, you are waiting for the next one to crop up on the next page. Grrr!

I suppose I am a book editor somewhat, in that I report errors on Kindle, however I would not in a printed book as there is no point, nothing could be done about the errors if the publisher does not know about them.