If you know his surname, you could probably guess at his address based on your own (first six letters of surname plus first initial?). And if that bounces, you could try e-mailing srecords@tcd.ie, which is apparently how one finds out student contact information. I figure they're more likely to give out contact info to another Trinity student than some random person. ;)

As for "If you give a mouse a cookie"... I'm not sure I ever read it, either, given that it came out in 1985... but then again, I certainly know the general idea. Anyway, just be glad it was (probably) a cultural thing, and not a generation gap problem — I once referenced Garbage Pail Kids in German, and most the other students (who were younger) were like, WTF?