The revolving door in financial services jobs shows no sign of stopping.

CIT Group, the commercial lender just emerging out of bankruptcy, hired John Thain as chairman and chief executive.

It's the same Thain who went on a spending spree to redecorate his new office when he joined Merrill Lynch just over a year ago, even though the bank was still suffering from bad bets on mortgages. Thain was also accused of hiding losses and extravagant bonus payments as Merrill Lynch was being sold to Bank of America.

But CIT is not the only firm with short-term memory.

The American International Group announced Monday that it hired Peter Hancock, former chief financial executive at J.P. Morgan until 2000, to oversee the insurer's finance and risk unit.

Hancock used to lead J.P. Morgan's derivatives and fixed-income units before making it to the CFO post. Remember, J.P. Morgan is the firm that popularized derivatives like credit default swaps and collateralized debt obligations, which caused much of the financial crisis, especially for Hancock's new boss, AIG. Hancock's salary at AIG is $1.5 billion in cash and $2.4 million in stock.

AIG also hired Thomas Russo last week as general counsel. Russo held the same post at Lehman Brothers before it filed for bankruptcy in September 2008.

AIG is hoping that his ties to the government - he held some positions at the Securities and Exchanges Commission and the Commodity Futures Trading Commission - will help strengthens the firm's finances.

But if revolving doors keep turning, firms will never learn from past mistakes.