Oh yeah, sometimes I want to rate some dramas higher and some dramas lower. But that would be a hassle, and I don't believe in my long-term memory (it could already be conveniently modified). Just rate it once right after you completed it and put it behind you. There'll be more dramas to watch and rate in the future.
As for mdl rating, it's the accumulation of many people's ratings. One rating, yours or mine, won't matter much. Feel free to rate it 10 or 1 (though I never completed any show that's so bad that I would give it a 1).
