Imagine that you are going on a hike to climb a high mountain like Mont Blanc. You have some cool friends with you and you have a great team that has a good chance to actually reach the top. All people in the team know what to do and how to do it; they are specialists in their own way.
Then suddenly your old Dad calls you up. By mistake, you had posted on Facebook (only old people use Facebook) that you are about to climb this mountain. Of course, old pap really wants to join in on this climb. In the height of his career, he climbed mountains. Mont Blanc was one of them. But that is back in the days and the routes he took are not available any longer. You are taking a totally different route. The equipment that is used is different. On top of that old Dad is walking with a cane and will just start nagging around things he did over thirty years ago.