My Gripe About Strangers Who Wave From Their Cars

I don't know how you're going to take this, but I have to get something off my chest. It has to do with the time honored gesture of waving "hello".  Hear me out folks, and then feel free to chime in from the comment section. 

I want to carefully word this..  I'm all for a friendly world - don't get me wrong.  People SHOULD be cordial to each other.  But here's what irritates me.

Take this scenario for example. You're mowing your lawn, which I like to do.  A car passes in the neighborhood. The person waves to me.  If it's someone I know - hey, that's great.  But if it's a stranger, I end up trying hard to peer into the car and wonder if it's a familiar face or not.. I feel guilty or unfriendly if I don't wave back, but then again I don't want to feel obligated to wave if i don't know the person.  I think that gesture should be reserved for someone I'm familiar with…like my neighbor.  Does that make any sense?

To me there should be some other kind of signal, like maybe a "thumbs up" or "OK" signal (you know - the circle you make with your thumb and forefinger) .  That would say "Hey - I don't really know you, but I'm making an attempt, and not EXPECTING you to respond".

Am I nuts or cruel for feeling this way?    Please let me know. Ok, now that I've alienated many who have read this, it is time to say goodbye.  (Oh crap -some people wave when they want to do that too!!) We also need another signal for THAT!!