It's natural to assume that your living expenses will go down in retirement. After all, you'll no longer have to bear the expense of commuting to work, and there's a good chance that by that point, you'll have paid off your mortgage. But surprisingly enough, close to 50% of seniors end up spending more money, not less, during their first two years of retirement than they did while working full time, and for 33% of retirees, this trend continues for a total of six years.It therefore never hurts to have an additional means of generating income during retirement in case your savings and Social Security benefits don't wind up cutting it.