I wish I had made newlines more significant in JS back in those ten days in May, 1995.
I wish Brendan was not as skilled a hacker as he was. It's an amazing achievement that he produced Javascript in such a short time. Unfortunately it ended up having the sorts of flaws that are inevitable with such a timeframe, yet it was "good enough" so that everyone decided it was easier to live with the flaws than break compatibility and fix them. If the initial version of Javscript had been worse, we might be using a much better version today.