If you have a 100 gallon fresh water tank, that can add 834lbs just to have it full. Another 50lbs for the 6 gallons in the hot water tank. Two 20lb propane tanks add another 40lbs. Now you're at 924lbs. You haven't added groceries, clothing, chairs, barbecues, bikes, and so on.
It can add up quickly and unless you've actually weighed your loaded trailer, you are most likely underestimating how much weight you've added to it with your personal stuff.
Reality-wise, you should only have to "worry" about your GVWR when you buy the trailer and/or the tow vehicle. Once you've bought it and after adding everything in, if you are 4,500lbs under the GVWR, then you can pretty much safely "forget about it". However, if after adding everything in, you are within 50lbs of the GVWR, then you're going to have to consider it whenever you want to bring along something else.