Tis the awesome thing about ARMA in general, it's so large that you can play the same map, or even the same mission many times and have cool and unique experiences each time. Every time you set foot out of base you are in for a totaly unique experience.
Agreed, unlike the small maps most of are used to where you quickly learn every likely sniper spot, hidey hole and choke point, it takes quite a while to even recognize villages and learn your way around a map in ARMA without using the tactical map. It's not like everyone scurries off to their favorite spots at the start of a round.
I like the fact that you have to do at least some basic planning; how to get there, who's going and how to stay alive when you arrive.
PvP missions change things even more....