A、One night he forgot to lock the front door. B、One night he forgot locking the front door. C、One night he remembered to lock th

　　Many of us often complain that we cannot remember things or easily forget things. However, (22) memory, they say, is a matter of practice and exercise. If you have the wish and really make a conscious effort to remember things, then you can quite easily improve your ability to remember them. But even if you are successful, there are times when your memory seems to play tricks on you. It often happens that we remember things that did not really happen. (23) One morning last week, for example, I got up and found that I had left the front door unlocked all night, yet I clearly remembered locking it carefully the night before. What’s more, memory "tricks" work the other way as well. Once in a while, we remember not doing something and then find out that we did it. One day last month, for example, I was sitting in a barber shop waiting for my turn to get a haircut, and suddenly I realized that I got a haircut two days ago at the barber shop across the street from my office. Frequently, we seem to find something funny and amusing in incidents caused by people’s forgetfulness or absent-mindedness. (24) Stories about absent-mindedness have been told for years, and we never get tired of hearing new ones. (25) Unfortunately, however, absent-mindedness is not always funny. There are times when "tricks" of our memory can cause us great trouble.
　　22. What should we do if we want to have a good memory?
　　23. What can we learn about the speaker?
　　24. What can we infer about absent-mindedness from this passage?
　　25. What will absent-mindedness cause us sometimes according to the passage?