i loss my mark on eclipse

in the morning of this day after i'm wake up
i'm open my eclipse and i saw my mark when i select my variable is loss
dammmmm it....

but after 10 min. i saw in preference and see in this

PHP > Editor > Mark Occurrences

when i check in that checkbox ..... apply > save
my mark is came back ............ yeah :) ..................

if i loss my mark it's so busy to use Ctrl+F to find my variable
you thinks same like me ?