I do clean and inspect my bikes gear trains, brakes and cables, but I stopped packing my own bearings years ago. But a couple of years ago I had a mishap removing my gear cassette to replace a broken spoke. BBs everywhere! Luckily I was in our video sound stage and "regained my bearings". Anyways, I cleaned and degreased the unit, put in fresh grease and repacked the bearings. That was the first maintenance like that the bike had seen since I bought it 15 years earlier. It was like a different bike. I didn't realize how sluggish it had become. So I did the front and took the other bike in for its first service, probably since new 28 years earlier. (I had the bike only 4 years at that point, but my friend had bought it new in 1984 and didn't remember any servicing). That was a revelation, too. I now have a third bike and will have the bikes serviced regularly.