Yeah the smart ones usually don't fall for all that slick outer image, self-important act. Plenty of gals like a modest and chilled guy.
I wouldn't expect much attention if you don't make the effort and allow your great personality to penetrate. It takes effort. Possibly are you wanting attention from the wrong type of woman? I never go for the 'hot' ones, but prefer the cuties with a touch of unique individuality on display (the more the better)...a bit off the radar you could say. Nothing has worked for me at all but there you have it, advice from another invisible man. Yes yes, the blind leading the blind, I know...

it says so in the bible. just keep on doing what you are doing

Two ways to look at it.
1- not all successful people are show offs. Maybe you feel that way because of your own insecurities. Don't let your insecurities skew your outlook in life.

2- there are plenty of people who look down upon boastful nature. People who need to show off and be loud (not loud personality but desperately seeking attention by loud) makes people cringe with their desperate neediness for attention.

not everyone is a narcissist or narcissist-wannabe.

Humility and simplicity are beautiful traits. They have real substance and depth to them and will be truly appreciated, once a woman gets to know you. So the trouble is not women, and its not your wonderful traits, its just that humility and simplicity can be subtle, easy to miss at first glance. This may sound corny but to get yourself noticed (a.k.a. not invisible) you gotta stop that voice in your head that reinforces that you feel invisible. Maybe you think its only in your head, but you might be broadcasting that 'invisible me' in innumerable conscious and unconscious ways. Kick that thought to the curb and replace it with a better, more truthful, more positive self-statement! Your daily reality might take some time to catch up with the new visible you, but who cares?! At least you're taking action. I guess more obvious things would be to smile more, stand taller, maybe communicate by holding a door, notice other people, their dogs, their whatever....and comment. Do any little visible steps you can think of (short of not being true to you of course). Takes practice. I know. I hope you attract someone who really appreciates you.

One can be humble and unaffected without being meek.

The meek shall indeed inherit the earth, once everyone else is done with it and nothing of value remains. Don't be that guy. Self-confidence and self-acceptance are NOT the same as narcissism and conceit, so practice the former and avoid the latter.

If you're not sure of yourself, no one else should be sure of you either.

I, for one, prefer the non-show-offy types - provided they radiate a quiet strength and self-assuredness, as opposed to meekness and self-doubt. Humility is a great quality; just be sure that you own it and remain proud of who you are (I know that sounds contradictory, but hopefully you catch my drift).

You're kidding right?

You have to be rich to get any attention here pal.

Look around and count how many guys are doubling their girl on a bike and how many girls are riding shotgun in a BMW.

Men don't buy those cars because they are neat.

I'm stunned how many guys here do not get it.

and I much prefer the strong silent types to the loud, show off-y center of attention guys. Maybe, like you, the girls that appreciate your traits are harder to notice because they don't bring attention to themselves or put their feelings out there as much. Just something to keep in mind!