Change history gives you an overview of all the configurations you have done in your account.
Note: If you have several properties in the same account, you won’t be able to filter by them, something that Google should add.
To access this functionality, login in Google Analytics and click on “Admin”:
Select the account you want to view the changes (if you have more than one) and click on “Change History”:
And it will show you a list of all the changes that have been done in your account and who made them. You can also search the list:
Don’t rely only on this to keep track of important events in your site, use Annotations to keep track on them.