Not to get obssessed with it, but the W3C Validator is a great way to find small errors like mispelled attribute names, bad nested or unclosed tags or even wrong format on dates, even though many times they don't seem to bring any obvious problems, is good to keep your code clean.
Today, 9th of April 2014 is CSS Naked day. A day when web developers and designers undress their websites from their styles to promote web standards and best practices in web design.
I have to say I have mixed feeling towards what happened in the last two weeks regarding Brendan Eich's rise and fall at Mozilla.
The ignorant doesn't know he's missing something, and the careless knows it that there's something he does't know, but he doesn't care to find out what it is.