It’s in our muscle memory. Press Ctrl+F
in your favorite text editor to find something, provide find criteria, and hit the Find button. As always, we usually stick with the simple Find functionality of the text editor as it serves almost all of our basic search needs. But beneath Find dialog box, there is a powerful Find option, Use Regular Expressions which most seldom use.

Able to recall a correct regular expression when we need it most is rare. Which often leads to the hassle of googling regular expression and trying few failed attempts, and going back to simple Find. This is where following regular expressions cheatsheet comes handy for me.
Regular Expressions:
Have
foo
anywhere andbar
later in the same line.*foo.*bar
Have
foo
at the beginning of the line^\s{2,}foo
Have
foo
at the beginning of the line andbar
later in the same line^\s{2,}foo.*bar
Have
foo
in the commentted line.*//.*foo
Have
foo
inside double quotes^.*".*foo.*"
Have
foo
at the beginning or end of the word^.*".*\bfoo.*"
Have
foo
at the end of the linefoo\r?\n
Have
foo);
at the end of the linefoo\);\r?\n
Have
foo
but notbar
in the same line^.*foo.*(?!bar)
Have
foo
and{
in the next line.*foo.*\r?\n.*{