I’ve just spent about 90 minutes looking at the HTML5 and CSS3 specs for the first time. Brain asplode! My stories of web development headaches/heartaches from ten to fifteen years ago have to sound like the infirm rantings of an age-ravaged mind to anyone who has picked this stuff up in the last few years.
The <center> cannot hold
The best “you can’t parse Aitch Tea Em Ell with regex, have you considered using a parser?” screed ever written: http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags/1732454#1732454 […] HTML tags lea͠ki̧n͘g fr̶ǫm ̡yo͟ur eye͢s̸ ̛l̕ik͏e liquid pain […] is just effing brilliant.