Certain words are not indexed because they're so common - even with a full-text search enabled. The word "for" is on that list, so "Think For Yourself" won't get a hit, as well as "For No One". For your edification - here's the list....
Code:
'a',
'about',
'after',
'ago',
'all',
'almost',
'along',
'alot',
'also',
'am',
'an',
'and',
'answer',
'any',
'anybody',
'anybodys',
'anywhere',
'are',
'arent',
'around',
'as',
'ask',
'askd',
'at',
'bad',
'be',
'because',
'been',
'before',
'being',
'best',
'better',
'between',
'big',
'btw',
'but',
'by',
'can',
'cant',
'come',
'could',
'couldnt',
'day',
'days',
'days',
'did',
'didnt',
'do',
'does',
'doesnt',
'dont',
'down',
'each',
'etc',
'either',
'else',
'even',
'ever',
'every',
'everybody',
'everybodys',
'everyone',
'far',
'find',
'for',
'found',
'from',
'get',
'go',
'going',
'gone',
'good',
'got',
'gotten',
'had',
'has',
'have',
'havent',
'having',
'her',
'here',
'hers',
'him',
'his',
'home',
'how',
'hows',
'href',
'I',
'Ive',
'if',
'in',
'ini',
'into',
'is',
'isnt',
'it',
'its',
'its',
'just',
'know',
'large',
'less',
'like',
'liked',
'little',
'looking',
'look',
'looked',
'looking',
'lot',
'maybe',
'many',
'me',
'more',
'most',
'much',
'must',
'mustnt',
'my',
'near',
'need',
'never',
'new',
'news',
'no',
'none',
'not',
'nothing',
'now',
'of',
'off',
'often',
'old',
'on',
'once',
'only',
'oops',
'or',
'other',
'our',
'ours',
'out',
'over',
'page',
'please',
'put',
'question',
'questions',
'questioned',
'quote',
'rather',
'really',
'recent',
'said',
'saw',
'say',
'says',
'she',
'see',
'sees',
'should',
'sites',
'small',
'so',
'some',
'something',
'sometime',
'somewhere',
'soon',
'take',
'than',
'true',
'thank',
'that',
'thatd',
'thats',
'the',
'their',
'theirs',
'theres',
'theirs',
'them',
'then',
'there',
'these',
'they',
'theyll',
'theyd',
'theyre',
'this',
'those',
'though',
'through',
'thus',
'time',
'times',
'to',
'too',
'under',
'until',
'untrue',
'up',
'upon',
'use',
'users',
'version',
'very',
'via',
'want',
'was',
'way',
'we',
'well',
'went',
'were',
'werent',
'what',
'when',
'where',
'which',
'who',
'whom',
'whose',
'why',
'wide',
'will',
'with',
'within',
'without',
'wont',
'world',
'worse',
'worst',
'would',
'wrote',
'www',
'yes',
'yet',
'you',
'youd',
'youll',
'your',
'youre',
'yours',
'AFAIK',
'IIRC',
'LOL',
'ROTF',
'ROTFLMAO',
'YMMV'