It’s really not that complicated. The only other direction to go on I-65 is north.

Interstates with odd numbers run north and south. Even numbers run east and west.

Sure, but use Google maps and have a look at “i-435”
Three digits starting with even are loops, starting with odd are spurs. Thats why I-495 can be both the capital beltway and loop around boston

Similar overlaps over in NY with 87/287, and 95 does something shifty near there also.

BTW there are multiple I-495s and 2/5 are Spurs

Oh yeah, I always hated that. I used to visit my ex’s parents down in that direction and I knew the way from having driven it every year but if I tried to give directions I never could remember which is 287 and which is 278