Can you walk 2 blocks carrying 2 bags of groceries that weigh at least 10% of your body-weight in each hand? For most people, this is probably adequate for comfortable living, but depending upon what one enjoys doing, one may need to be able to carry heavier amounts.
Children are the perfect graduated weight-training program! They grow and get heavier, and they squirm, which can make carrying difficult.
Carrying heavy things for a few minutes from one place to another (from the store to the car, or from the car to the door) is something we often need to be able to do, so if you are injury-free, practice walking while carrying something heavy frequently enough that you remain strong enough to do it.