If one leaves a job and has money saved, is there something wrong with taking a few months to learn some new skills on one's own before spending time looking for another job? I'm guessing managers and headhunters would say "yes", but I say "no".
I'd guess managers and headhunters only respect what they consider "official" work or academic experience, with some outside influence (company or school) putting pressure on the individual to deliver. I'd guess they also don't trust that such time was spent on legitimate activities.
I think that if one is laid off there is no foul, and since companies can lay employees off anytime it is convenient for them, there is no foul for leaving with notice either (companies don't even give any lay-off notice of which I know). I also think learning new skills on one's own time (which is seriously one's own time when one has no job) is admirable and shows motivation. The ability to learn on one's own is certainly a realistic exercise since there is usually not time while working at a job to stop and take an "official" course in every area one has to work. Also, there is the added benefit that the next employer doesn't incur any of the cost of this learning period. If the next employer has a related project then the individual will be ready to start working on it.
Basically, I think "official" "work" or "school" is overrated and as usual rewards the mediocre rather than those who stand out and excel.
I've certainly learned more by writing code, talking to other developers (counting newsgroups), and reading than I ever did earning my Bachelor of Science degree. 5 years wasted. :-)