> An expert is a man who has made all the mistakes which > can be made, in a narrow field. - Niels Bohr
I don't think most people can be experts in couple of things, as it requires too much time to be expert in at least one of them (but there are always an exceptions).
I agree it is good to know a lot of things but I doubt one can be master of all trades. These days even car mechanics get specialized for a brand of cars.
In area of web design there is a myriad of technologies included in the process of developing a web site or an application.
There is HTML/CSS frontend, there are server side apps (in all kinds of languages), there are couple of web servers, there are few platforms on which those web servers run, and there is a database layer.
You can be an expert in any of these, but hardly all of them, since most of these are generic terms. What kind of database? There are experts for Oracle, there are experts for Postgres, experts for MSSQL etc... Then there are those who excel in maintaining web servers either nginx or apache or IIS etc, there are those who are experts in node.js there are experts in Django. And you could go deeper and deeper still.
And this is just a development part, if you put graphics design into picture there are wast number of options from which to choose that you can be expert in.
But do keep in mind I am talking about being an expert, you can have sufficient knowledge in HTML/CSS/Server side apps/Web servers/Databases to build a web site but you will hardly ever be expert in all of them.
Maybe I am wrong, but I do agree that it is near impossible to be expert in couple of things.