I tried your example, and got what seem to be non-deterministic results. The first time I searched for "I'm not a mathematician or a puzzler", I got "No result

I tried your example, and got what seem to be non-deterministic results. The first time I searched for "I'm not a mathematician or a puzzler", I got "No results", plus a long list of results for the same search without the quotes (which did not include solipsys.co.uk). I switched to Verbatim, and still got "No results", but no list of alternatives without the quotes. I then tried regular and Verbatim without the apostrophe in "I'm" ("Im", in case it was indexed without punctuation) and got the same non-results. Then I tried misspelling "mathmatician" an suddenly I got the hit on your site as a suggested alternative! Then I tried a regular search of the original correct phrase, and got your site as one would expect! Then I switched to Verbatim and again got "No results". I'm not sure what to make of this, but since the same search a couple minutes apart produced different results, there must be something happening behind the scenes. Maybe the different backends have different versions of the index, and Verbatim only uses the version without this phrase? Or maybe it's just chance and if one kept trying, one would eventually get it to work with Verbatim.