Keira Knightley says acting can be like a drug

London: Keira Knightley has admitted that acting is like a drug for her, only as long as it is going well.

The 28-year-old singer claimed that she loves getting inside somebody`s head while acting, adding that for a second between action and cut, there will be a couple of times where it feels absolutely real.

Knightley claimed that moment to be magic, where those words are completely your own and if it`s going well, you get it twice a day but if it`s not, you don`t get it at all.