Thank you already

I got a couple of compliments yesterday at work. They were for my work and my looks from two different people who had not seen me for a while. Harmless stuff but still complimentary and it still threw me off kilter when it happened. It always does and I don’t know that it is worth my time anymore to try to figure out why. 
If I get feedback on something I need to change I can immediately start processing what I need to do to put that into motion. I can work out steps if it is complicated or jump right to a better procedure if it’s something simple.
If someone just surprises me with a compliment I have nowhere to go with it. I’m stuck. It is put out there and I’m supposed to do what with it? What do I do with it?
I have tried to train myself and I can hear my brain immediately kick in when it happens, “Say thank you, say thank you…hurry up and say thank you.”
“Thank you,” I finally say. But it doesn’t seem right. Thank you? Sounds lame, besides I haven’t had a chance to see if I really believe what they are telling me anyway. Am I allowed to say thank you if I don’t think it’s true? I’ve been ambushed and haven’t had a chance to think this through yet.
So that’s why I’ve tried to train myself to just say Thank you. ‘Cuz I don’t know what else I’m supposed to do and I’ve found that it seems to be rude when you ignore it or act like you don’t believe them or argue the point.
I’ve tried to pay attention when other people get compliments so I can try to steal their responses. I can’t seem to remember how they respond. They do it so seamlessly, like nothing, and it is over and done with before I realize I don’t know how they responded.
Then I am left thinking how did they do that? That whole exchange came and went and what…? Like it didn’t stick, or maybe it did and I’m the only one who really takes this stuff seriously. Maybe that’s it. I am making it more than it is and I have been know to do that - to take things too seriously. I should just shrug it off like it is nothing. But wait, that wouldn’t come off right either.
So I guess I should just hope it doesn’t happen again too soon and I will try to stick with the immediate Thank you response and leave it at that.
Geez.
TT