>>And I thought I was observant! :-)
>
>Interesting. Can we use the word "observant" in this context? I thought it referrs to religios person, who observes all the rules dictated by his/her religion. Such as in "an observant Jew".

At least in norwegian you can, so I thought you could in english also. Observant means to be alert or good at spotting details. I searched "define observant" on Google, and found paying close attention especially to detail.