I entered Turkey from Georgia using my national ID Card and got a filled-out form with an entry stamp.
I then lost it while in Istanbul. The Police told me I could simply explain it when exiting and there'd be no issues.
When exiting by bus to Bulgaria, I got a new form with only an illegible exit stamp (not filled out). They refused to re-stamp it to make it legible.
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Should I save this form and present it next time visiting Turkey? Could it possibly make my entry easier?
I don't think this form has any significance, because your actual departure and arrival is recorded in the immigration system; and not determined by some easily misplaced piece of paper.
That may not even apply to you - as you are entitled to free entry to Turkey due to your EU status.
This paper has no value once you have exited the country - except perhaps as to serve as a secondary proof that you have visited the country.
If and only if you are questioned about your travel history should you present it. If you just volunteer this it may just cause further confusion.
