There is a reason why kids term people who are married or have kids, old. Because we are! We decide without realizing that being married and having kids demands acting a certain way, being a certain way. We also tend to, during that process forget about things that can/are as satisfying as having a heated discussion on politics.
Now if you hang out with your child often, you will find yourself wanting to paint a little longer, swing a little higher and knead the playdough a bit longer.You find yourself hooked, to the simpler things in life.
So embrace it, enjoy it and love it.
No one needs to know you also prefer painting your fingers with different colors to the over rated white piece of paper.