I dropped my keys. I cannot find them. I lost them. I should have used my money to buy medicine for my grandmother, but I wasted it on candy instead. My boss made me work late, so I lost time to study for my test. I should have studied for my test, but I wasted time watching TV instead. lost= something bad happened to me wasted=I did something stupid.

lose like something happened without your approval or agreement but waste is like you do it by your self and you waste it on ridiculous things ( that's my opinion)