Keep waving someone who has closed his eyes only when you understand the fact that you are only exhausting your energy with the hope that one day he will open his eyes and see you waving him!

Funny enough, I sit on my porch all day, wave and smile at everyone. Some of them aren't sure, some smiles right back, some come back later and say; "This morning you made my day, had the best day all week, thank you for that!" Smile and wave, that's all it takes :)