You can retrieve the state of your text as it was some time ago. This concept is called undo tree or undo branches.

Moving through the undo tree

Go to newer/older text state.

g+
g-

Go to older text state, 10 minutes before.

:earlier 10m

Go to newer text state, 5 minutes later.

:later 5m

Using g- and g+ will get you to all possible text states while repeating u and CTRL-R does not.

See also :help undo-branches.