I? think? interest? is? very? important . First? of? all , only? if? you? are? interested? in? it? can? you? focus? your? efforts? on? achieving? it . What's? more ,? interest? is? the? driving? force? of? progress . I'm? convinced? that? the? only? thing? that? kept? me? going? was? that? I? loved? what? I? did . You've? got? to? find? what? you? love , and? that? is? as? ture? for? work? as? it is? for? your? lovers . Then , interest? can? have? a? positive? effect , make? people? study? hard .