Social benefit repayment (line 235) isn't correlated with not working for 8 years. There are two instances where line 235 shows up:
A ) if you receive Old Age pension (reported on T4A-OAS)
B) if you receive employment insurance benefit (T4-E)
See this link http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns206-236/235/s-eng.html if you received T4A-OAS.
See this link http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns206-236/235/ei-eng.html if you received T4-E.
If your situation falls under any of the two categories above, line 235 will be generated. It is a calculated field so do not remove it. Contact us if none of the two situations apply & you still see line 235.