Existing research emphasizes unequal opportunity as central to concerns about economic inequality, suggesting that fair competition mitigates concerns about unequal outcomes. However, past work overlooks the potential for individuals to take for granted different levels of economic inequality, implying that outcome inequality may operate on a distinct cognitive level in shaping normative concerns about fairness. To test this, we conduct an online experiment (N=3,335) that simultaneously manipulates opportunity and outcome distributions in a multi-round game setting, thus creating and assigning individuals to environments with different levels of outcome and opportunity inequality. We assess fairness concerns through in-game attitudes, responses to GSS-based inequality questions, and behavior in Dictator and Ultimatum games. Consistent with prior work, the results show that both winners and losers oppose unequal opportunities regardless of the different levels of outcome inequality, though the intensity of their opposition varies. However, their ideal levels of inequality consistently mirror their experienced outcome inequality, irrespective of opportunity distribution. This suggests that individuals naturalize experienced inequality of outcomes. Notably, we find no corresponding effects on behavioral measures. Overall, these findings highlight that while individuals generally uphold the principle of equal opportunity, they also internalize and accept their experienced level of economic inequality, demonstrating the powerful influence of habituation on fairness concerns.