That's true, but I wanted to at least be as composed as possible. I did have it all printed out just in case so my brother-in-law could step in if he had to.
My reasoning for doing it was more that his church had a newer priest that didn't know him (my Dad had some major mobility issues his last few years), so I wanted something better for him than the quick blurb from our conversation with the priest.
The only other one I had done was for one of my friends. His family had several of us share some stories, but that didn't seem too eulogy-ish.
EDIT- Forgot, I did say a few words at my father-in-law's as well. The pastor they had must not have read his notes very well (kept calling him Greg instead of Craig), so when they asked if any family wanted to speak I helped get the ball rolling for my wife and her sisters.