The bain of a sysadmin’s existence is documention. Most of us hate doing the tedious paperwork, but doing so helps the group around you and many times yourself once you’ve moved on to new projects. I know its a struggle for me and my co-workers.
Part of the problem is that documentation tends to get outdated. Keeping your notes updated as changes are made is tough. Old documentation is sometimes worse than no documentation… Its sometimes better to get inside and dig around to see how things are actually working/setup.