think about指“考虑,回想,想起”多用来指“考虑某事情或对某事进行思考”
,侧重于用大脑去思考,回想...如：
(1)He is thinking about travelling in the summer holidays.他正在考虑暑假旅游的事.
(2)She was thinking about her childhood days.她正回想她的童年时期.
而want to意思是想要干.后接动词原型,常用短语want to do sth.侧重于人的主观愿望,如
(1)I want to have a bottle of water.
(2)He want to be a singer when he grows up.(这里的想成为这一动作,也是人的主观愿望）
think about和 want to在本意上有很大区别,可以说这两个词没有什么联系,只不过在汉语中都有“想”,但是没有联系,要分清楚哦