Andy T, the local expert on Urban Exploration (those words again), has a different attitude on writing "correct" webpages, as shown in this posting to Slashdot recently. The difference is that Andy has something interesting to put on his website, so needn’t worry too much about the technicalities of it, whereas me and Sam have only the sites themselves to show off.
Anyway, if you want to see how extreme properly writing websites can become, have a read of Ian Hicksons critique of other peoples websites (Markup Challenge: diveintomark.org and Markup Challenge: aaronsw.com). Hixie knows what he’s talking about; he works on standards compliance for Mozilla. He ran a quiz over the summer to find markup errors in a document that validates fully with the w3 validator. I was quite proud to find three of the four errors in the document, but even then, I’ll not pretend that my own pages are perfect.