Love is blind

In the very beginning, people who fall into love are hard to find each other's weakness. Because they wish everything is perfect without shortages, they even considered it as strength when others  consider it as weakness .

After a period, they found the person who had many weaknesses. For example, a girl saw her ex boyfriend after they broke up for a year, she found he is not handsome as before.

It can be explained by the followings:

Firstly, the first impression will last for a long time. If you give a good first impression  to people, it would leave primary effects.

Secondly,because of this effects,you can't distinguish the bad  things from the good things.

Thirdly, don't judge a person by appearance, don't judge a book by its cover.