The main point about regex matches is that the regex engine will always give you the first possible match, i.e. if you try to match the string "bbaababaaaa" with the regex /a+/ or /a+?/ the match will start on the first "a" of the string irrespective of greediness. With the greedy operator you'll get the first "aa" and with non greedy "a". The fact that you used a greedy quantifier will still not lead to the "better" match at the end of the string: as soon as there is a possible match, there will not be backtracking to look for "aaaa". Similarly, with a non greedy quantifier, the regex engine will not give up the start of match if it found one. In other words, greediness should be understood "forward, or "to the right" only, not backward.

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