If you have hit 60 with just a few minor niggles to your back and shoulders then good luck to you. Not being able to lift 20kg cabs has in many cases absolutely nothing to do with 'hitting the gym'. Certainy in my case. For most of my adult life I used to go to the gym 3 or 4 times a week. In my late 40s I used to bench press 100 kg for reps and 200kgs squats for reps which didn't qualify me as superman but meant I was fairly strong. I am now 64, have been nursing a prolapsed disc for some years and, on some mornings, struggle to put my socks on. Rather than lift weights I do core exercise and yoga stretches every day. I also walk. I can and do lift the 22kg pa bins without a problem. Getting them into just the right position in the car is sometimes a struggle. As is getting them up and down stairs. Because, for me, a slight twist in the wrong direction whilst carrying them means I am on the bench for a fortnight.
But like so many on here you seem keen to be scornful over things that are different to your own experience. Please consider that there other situations and viewpoints.