i think it depends on where you go. if stateside or a cruise,sure. but overseas i think you need 10 days-2 weeks.
Just general knowledge type stuff, or odd laws, or weird court cases, unusual facts ...
This one always stuck out to me - the fact that a simple deck of cards contains so much information:
80,658,175,170,943,900,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000Possible unique orders of cards in a standard 52 card deck (52!) 436,117,076,600,000,000Approximate age of the universe in seconds 0.0000000000000000000000000000000000000000000000005407%Approximate age of the universe in seconds as a percentage of 52!