Marked man

Interesting experience at Southampton airport @ 0615 this morning - boarding my flight to Amsterdam, a person from immigration control asked to see my passport- I was then questioned as to whether I was flying onwards from amsterdam and what my business there was?
Having flicked through my stamp pages he then commented - "you have a lot of Middle east stamps in your passport sir" - why is that and what is your line of business ?
I have to admit all sort of answers that would not have got me on my plane, so I simply said - "I like visiting there and I work in Chemicals" to see whether I would get further reaction. He grunted a thank you and moved on to the next passenger.
So perhaps I am "a marked man" because of passport stamps ?