I'd say there are two learning curves involved. The first is knowing what every symbol does. This sounds like it will be quite hard, but honestly probably takes

I'd say there are two learning curves involved. The first is knowing what every symbol does. This sounds like it will be quite hard, but honestly probably takes less than a day. APL really doesn't have a lot of stuff to remember. It just looks a bit weird. The second learning curve however is the much harder part, learning how to write APL 'idiomatically'. This is mostly true in any language though, especially one in a different paradigm.