\expandafter\protected@edef\csname p@\@enumctr\endcsname
             {\csname labelenum\romannumeral\numexpr\@enumdepth - 1\relax\endcsname}%

I am the psychotherapist.  Please, describe your problems.  Each time
you are finished talking, type RET twice.

why this doesn't do what I think it should do
\expandafter\protected@edef\csname p@\@enumctr\endcsname
             {\csname labelenum\romannumeral\numexpr\@enumdepth - 1\relax\endcsname}%

Why do you say that?
because I wrote it



Is it because you wrote it that you came to me?

\documentclass[]{article}
\usepackage{enumerate}
%opening
\title{}
\author{}

\makeatletter

\let\old@@enum@\@@enum@
\def\@@enum@{%
\expandafter\protected@edef\csname p@\@enumctr\endcsname
             {\csname labelenum\romannumeral\numexpr\@enumdepth - 1\relax\endcsname}%
\old@@enum@}

\begin{document}

\begin{enumerate}
\item 1st item
\begin{enumerate}[\theenumi.1.]
\item 1st nested item
\item 2nd nested item
\begin{enumerate}[\theenumii.1.]
\item Useful/Important Information\label{a}
\end{enumerate}

\documentclass[tikz]{standalone}
\definecolor{cffcc00}{RGB}{255,204,0}
\definecolor{c008000}{RGB}{0,128,0}
\definecolor{caa8800}{RGB}{170,136,0}
\definecolor{cd4aa00}{RGB}{212,170,0}
\definecolor{ce6e6e6}{RGB}{230,230,230}
\begin{document}
\begin{tikzpicture}

\draw[white,fill=cd4aa00,line width=1pt] (-102:1.3)to[in=115,out=-84]++(-75:0.61) to[out=
25,in=180]++(10:0.42)to[in=35,out =-90]++(-122:0.365)to[in=-65,out=170]++(150:0.33)to[out
=108,in=-65]++(112:0.63)--cycle; \fill[cffcc00](-2,0)arc(180:230:1.5 and 1.8)arc(240:320:

Testing out...

     \documentclass{scrartcl}

     \usepackage[T1]{fontenc}

     \addtokomafont{section}{\centering\rmfamily\scshape}

     \begin{document}

     \section{Sample Section}
     Sample text.

     \end{document}