There are two reasons for this. FORTH, to an honesty significant extent, only supplies the tools whereby a user can construct a language that looks as he wants it to. Second, there are 200 words in the dictionary, all of which are intended to be used - and therefore must be explained.
Moreover, although we claim significant compactness of FORTH programs, such compactness is not apparent in small examples. It arises through the economies of tailoring definitions to a specific application. It is the case that our small programs are smaller than your small program, but our large programs are much smaller than your large programs.
Nevertheless, we can try to give you an impression of FORTH's language by some brief discussion and a simple example.