can anyone explain briefly to me what the following phrase means?
A thunderous silence breaks through my thoughts.
What was once many great ideas is now a triumph, lost.
It's a play on words. Common collocations for 'thunderous' are 'applause' and 'reception'. 'Thunderous silence' doesn't make literal sense; but it's an emphatic way of saying 'my ideas were unpopular or not met with much interest (if any)'.