Podcasts revisited

I have become quite involved in downloading podcasts and also putting talking books onto my ipod. Just wanted to note one thing that may be obvious to others however to me...no. Initially I plugged my ipod into a Mac and then onto my PC and I did not realise than an ipod can only be used on one computer. It has taken time to correct this mistake as I want to use my ipod with my PC laptop. Did others know this?