how to reset vim's settings (including plugins, .vimrc file) without close vim?

Question

I have been using vim for two years, and I use "pathogen" for plugins manage. I am seeking a way to reset all vim's settings (including plugins, .vimrc file) without close vim. Is there any idea?

PS: In some cases, reload vimrc doesnot work exactly the same as reopen vim, so I want to reload the whole state exactly like reopen vim.

Answer 1

From :h set

:se[t] all&             Set all options, except terminal options, to their
                            default value.  The values of 'term', 'lines' and
                            'columns' are not changed. {not in Vi}