As your child grows up one of the most exciting parts of their growth is seeing them develop parts of you or your spouse. Some of the parts are not so good like the ability to lose things over and over again but many are great such as seeing your creativity in a musical score or painting that they’ve produced. You can fight with your spouse which parts belong to whom ( in my case the big nose and ears belong to me, sorry) but knowing that you’ve truly played a role in seeing this (G-D willing)wonderful person develop from a child to an adult is something that keeps you living even after you’re parts are getting a bit run down in your own body.
It also inspires you to help your child get through the situations they will encounter better then you did with the same type of parts. For whatever you weren’t able to foresee in your future can be seen in the eye’s of your child who allows your legacy to go in different exciting directions that your parts didn’t go in your time.