滋长

滋长 is used for abstract qualities — typically negative ones: bureaucracy, arrogance, complacency, bad habits. Almost never for physical growth (use 生长 shēngzhǎng or 成长 chéngzhǎng for that). Compare with 助长 (zhùzhǎng, "to abet/encourage") which has a similar pejorative tilt.

memory

滋 (to nourish/moisten) + 长 (to grow). Like a weed nourished by neglect — the negative connotation comes from the kind of growth implied: slow, unwanted, hard to root out.