Can anybody figure out what this even means?

Can anybody figure out what this even means?  A tweet from That One yesterday:

President Obama: "We are here today because we know we cannot be complacent. History travels not only forwards, but backwards and sideways."

That's not something I made up – it was tweeted from the White House account.  Click the link to see it for yourself.

No matter how I squint at that, it's still nonsense.  I can't see any way a typo could have caused it.  I think it's really just nonsense!