No, that's not idealistic, that's down right delusional
But...yeah, being an idealist means that you understand how the world is but always hope for better, believing in change, believing you can make a difference, and unfortunately sometimes retreating into a sort of fantasy world to be able to cope until you're strong enough to go out there and make changes again.
Being an idealist means dreaming up schemes and actually going through with things other people only wish they could do, or say they'd like to do someday "only if" but never get around to it...we're actually crazy enough to do it NOW, and sometimes we win.
We don't always win of course, and we can take it pretty hard when we don't.
Being an idealist means looking for the good in people even when you understand there's bad in everyone.
Being an idealist means foolishly believing my little rants might actually change someone's mind or behavior.
Being an idealist means being disappointed a lot, but it also means being hopeful and loving a whole lot too.
We go out on a limb, and like, live there on that tenuous branch, hoping for someone who understands us to join us so someone will catch us if we fall from our fabulous dreams.