real life, it means that she is interested and probably in love with him. of course, this indication does not prove that the woman is in love with the man on its own but in fact different combinations of indications prove love.
seeing you happy and excited talking about your interests makes her happy and that is why she bothers enough to spend all that time getting to know what those interests are and why they have caught your attention. she also knows it will make you more interested in getting to know her in return if she does so. it does not matter how boring that activity is, a woman 