Reese Witherspoon found the period in her life while divorcing Ryan Phillippe to be a ''challenge''.

The 'This Means War' actress - who divorced the actor in 2007 after an eight-year marriage - now feels much ''stronger'' and has learnt ''so much'' from the difficult life experience.

Reese - who has children Ava, 12, and Deacon, eight, with Ryan - said: ''That period in my life was a challenge but you feel so much stronger once you pick up the pieces and make a new world for yourself.

''You rethink a lot of things and you develop a much sharper sense of what is going to make you happy. Many people go through crossroads in their lives, times where everything falls apart and you don't know what to do next.

''But you learn so much and it makes decisions easier going forward.''

Reese - who married talent agent Jim Toth last year - believes relationships need a lot of ''negotiation'' in order to be successful.

She added: ''You have to be ready for a relationship so once you are finally in the right situation, I think you have to be willing to compromise and negotiate.

''I don't think it's war, but I do think it's a negotiation.''