You must have been troubled by when to say 'I love you' because it is one of the greatest puzzles in our life. What if you say it first and your partner doesn't love you back'? Or if they do say it but you don't feel they mean it? Being the first to declare your love can be nerve-racking (紧张) and risky and can leave you feeling as vulnerable as a turtle with no shell. But is the person who says it first really in a position of weakness? Doesn't it pay to hold back, play it cool and wait until the other half has shown their hand first? 'A really good relationship should be about being fair and being equal,' says psychologist Sidney Crown. 'But love is seldom equal.' All relationships go through power struggles but, he says, if a love imbalance continues for years, the rot will set in. 'That feeling of 'I've always loved you more' may be subverted (颠覆，破坏) for a time, but it never goes away completely and it often emerges in squabbling (大声争吵).' In love, at least, the silent, withholding type is not always the most powerful. 'The strongest one in a relationship is often the person who feels confident enough to talk about their feelings,' says educational psychologist Ingrid Collins. Psychosexual therapist Paula Hall agrees. 'The one with the upper hand is often the person who takes the initiative. In fact, the person who says 'I love you' first may also be the one who says 'I'm bored with you' first.' Hall believes that much depends on how 'I love you' is said and the motivation of the person saying it. 'Is it said when they're drunk? Is it said before their partner files off on holiday, and what it really means is 'Please don't be unfaithful to me'? By saying 'I love you', they really saying Do you love me?' If so, wouldn't it just be more honest to say that?' Collins agrees that intention is everything. 'It's not what is said, but how it's said. What it comas down to is the sincerity of the speaker.' What is the main idea of this passage?