"I" preceding another subject?

[dihen]

Why do many grammar books consider "I" preceding another subject, such as in "I and you" incorrect? Is it actually ungrammatical, or is it so unnatural that it is considered incorrect?

[Tdol]

I think it's just unnatural. In speech you will hear people using it, when they think of a second subject as they talk:
I... and my father... went
This suggests to me that it's not a grammatical issue, but one of colligation, unlike the use oif 'me and John went', where there is a clearcut grammatical issue.

[Casiopea]

'[I]t’s polite and grammatical to put yourself last in a list of people ...' (Chicago Manual of Style - Q & A - pronouns)