Hm, and how do you know if you need this or, say, that particular thing to complete your task or not?
I usually see a lot of really bad PHP code which as a rule accomplishes a task to some degree. The thing that strikes me is this: how the hell hard it could be when you just don't know what a regexp is? (And the majority of PHP coders are unlikely to know.) Nobody here will argue that regexps are, mildly saying, useful, but, as the experience shows, optional.
I know people out there writing translators from scratch because they don't know what flex and yacc are and I even know people using perl4 features as described in their aged book! Examples are numerous and the conclusion is that you should probably study hard the things you really need, but please please at least explore as many things as you can just not to miss an opportunity.
