To those who are in Yeshiva, learning Gemara for three sedarim a day is often a regular sight. To those who are actually learning it, it's often an extremely rewarding experience, and one in which those learning can often get so deeply involved in it that they completely lose track of time.
To one who knows what the Talmud is but has never actually learned it himself, this can be less intuitive: how is it that a bunch of guys can read those ancient squiggly letters, yell at each other for hours on end over what it's saying, and both of them enjoy the entire experience - and walk away best of friends?1
How does one answer these sorts of questions? How can I explain to someone why Talmud is so exciting, enjoyable, and rewarding (even in this world)? You can assume that this person has zero personal Jewish background (read: isn’t Jewish) but knows the basics about Judaism's beliefs and fundamentals.2
1Paraphrase of Kiddushin 30b
2Similar questions such as these have been asked before, so this shouldn't be off-topic (at least not for that reason).