I also like the the fact it's tricky to spot when people use use double words in in their sentences. You might spot one or two but if if done often enough you'll miss one.
We're told as kids not to start sentences with and, because etc to make it clear they're connecting words, rather than words that start new sentences. In reality it's fine to use them to start a sentence in a correct case. For example 'because' usually explains something earlier in the...