That's just it - it sounds easy enough, but odds are that you would aspirate the "T", make the "ee" just a tad too long, and turn the "o" into an "ough" of some sort when it must be but a single sound, not a diphthong of any sort. You would immediately reveal yourself for a foreigner in Finland just by calling me by my given name.
Spock might be unable to stand all the little things that are wrong with how Kirk attempts to pronounce his surname... Although Kirk probably has Spock's given name down pat, considering Spock's own father pronounces it the exact same way. That is, unless Sarek uses the human-style pronunciation as a subtle insult to his son.