Why Is The Sea Salty?

'Hey Max, do you know why the sea is salty but a river isn't?'

'No, Max. Why are you asking me that?'

'Aren't you interested?'

'Well, I've got other things to focus on.'

'Like what?'

'You know, the daily stuff I need to do.'

'But don't you think it's a primary question?'

'My primary question at the moment is which price plan to choose for my mobile.' 

'Well, let me tell you: so over millions of years, the seas have been accumulating salt washed off the land by rain water as it finds its way via rivers, both above and below ground, back into the sea. So fresh water is actually salty too but the concentration of salt is too low for us to notice.'

'Do I need unlimited texts? I don't actually send that many...'