The best part of life long learning is playing and learning. Okay it sounds hokey, it sounds corny, but learning something new everyday is why I became a librarian, and why I stay a librarian. I am like a sponge, tell me something that interests me and I have to soak up as much information as I can find. I know that is why I took to the Internet like a duck to water, I was surfing before it was called surfing, remember gophers, telnet, FTP, and USENET. I remember (now I sound like some old geezer) when the only thing you could "pull up" were text based lists and catalogs. We were all going, "where did you go today" and "wow, I went to the catalog of the University of London". Enough of the old days. Now there is Web 2.0, so much information! I think we all tend to get overload.
The hardest part of lifelong learning for me, when learning something new, are the set backs. I often view these sometimes little problems as big problems. But I persevere.
Best part of learning something new, is using it everyday and teaching others. I love to see the smile on some one's face when something I have passed along sparks their interest.