One of the things we get better at doing after the age of 25 is evaluating risk. Your brain is just beginning to integrate your experiences to process what risk mitigation is, and how to predict the likelihood and severity of risks that may happen.
It sounds like you're invested in cashflowing real estate, which is great. But what would happen if one of your tenants runs into problems, and stops paying? What if you have to go through an eviction, or there is damage to the property? What if there is a fire?
Real estate in particular carries some unique risks, all of which can be planned for and managed. Are you setting aside a maintenance fund to replace the roof, or a furnace, or rehab and refresh the apartments on a regular basis?
So the benefit of saving half your income is that you can diversify out of real estate to some other investments - equities would be ideal at your early age. Do you have an emergency fund? Have you set up IRA's?