In which language do you think when you speak

My routine trip to the office supply store this morning .. me multi tasking in my business casual clothes roaming the isles , buying stuff while talking with someone on the phone.. nothing exciting so far... no I was not loud or obnoxious.. I never am ;)... There is hardly anyone in this big store....after about five mins I notice a middle age lady well dressed in business suite doing her shopping sort of around the area where I was... the noise of her high heel pumps is slightly annoying ....I may have glanced and light smiled at her .. not exactly remember since I was so busy discussing /solving world problems over the phone..

After another 5-10 mins, I am on my way to cashier's lane... Only one open lane and a person in front of me has problem with price or something...( Murphy's law..always ) Anyway... so I am patiently waiting for them to get the resolution and I see this lady come stand behind me... She said hi and I said hi back... ( maybe vice verse... still not paying to much attention to her) .. and here's how the conversation went after that...

Lady : "Excuse me,but I briefly heard you talk .. you speak very good English "

Hmm...within a flash of second, few thoughts crossed my mind.. Honestly, I don't consider it a complement anymore.... Then I checked and made sure my wedding rock was clearly visible on my finger ( hey, these days you never know when total strangers start praising you ) .. Second thought was probably what was I talking on phone ( no breach of privacy for anyone) .. Third of course was annoyance that this unknown woman had no business listening to me ... and I am sure few more flash thoughts along those lines.. Slightly irritated I just glance back at her and she continuse.

Lady : " you look Indian .. I am always curious what language you people think when you speak .. is it your native language or straight English ? "

By this time, I was greeted by cashier... I turn back and with a straight face I said " neither.. I don't know... maybe in polish " ..

I seriously had no intention of pranking her or anything but I was purely annoyed at her now...  I just wanted to get out and maybe a quick joke to lighten her up along the way.... I am swiping my card at this point so I am almost done.. and I hear her one last time in the back,

Lady : " Oh really, my best friend is Polish too... But sorry you don't look Polish ... are you married to one? "

With a BIG awe and smile on my face I just nodded and walked away... wish I had friend along for a good hard laugh....