Don't start the countdown until you've fetched a user

[oliverjam]

It's a bit strange to start losing experience before I've even chosen my user 😉

In order to share the state between the two child components you may want to look into the concept of "lifting state up". I talked about the general concept in this issue

There's an article in the React docs about this https://reactjs.org/docs/lifting-state-up.html