• 1. I shouldn't trust so easily in what others say.
• 2. I should frequently practice with my monitor some oneliners with the examples that I learn...

perl -e"$old='abc';$old = tr/a/z/g;print \"$old \n\";"
Bareword found where operator expected at -e line 1, near "tr/a/z/g"
syntax error at -e line 1, near "tr/a/z/g"
Execution of -e aborted due to compilation errors.
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There is no tr///g since every replacement is done on all the characters. So the /g would always be unnecesary. Just try it!

.{\('v')/}   C H E E R   U P !
 _`(___)' ___a_l_b_e_r_t_o_________