Still very much the wrong approach. I can see why you had the demo-mode on the landing page, although I think it isn't necessary, but there's really no reason to have it all once you're interacting with the site.

Another side effect is that sometimes I accidentally skip sentences that start with s because i invariably forget to press enter before starting.

I also did this several times initially.

Smart defaults. Requiring enter to start is not smart. It just isn't. Sorry.

You can have a big start-typing button at the home page (initially). But when we select a lesson from the select box or retrying a lesson, it would be great if we could able to start typing immediately.