With everything we humans do, well, almost everything, we are in contact with other people. We call, email, app, meet, talk, watch and observe. Most of us are whole social animals and can't live without contact with others. Some people have a lot of contacts, others have a smaller circle of friends and acquaintances. But one thing we all have in common is maintaining contacts with others. That's human.
How one maintains contacts, and certainly how often and how much contact one has differs greatly. Some people have many different appointments and calls with others every week. While others only have a few contacts a week, or perhaps always see the same people instead of meeting up with many different people. Hardly anyone can do without contact with others.
Everyone also maintains contact in his or her own way. There's no right or wrong. Although of course there are different manners that are wise to follow if you want to connect with others. In groups, there are often unwritten rules on how to interact with each other. Whether that's about greeting, touching or what you say or not, every group or culture does this differently.
Which, of course, is always wise to maintain your contacts, to make sure you remember what was discussed in previous conversations. And what your interlocutor likes or doesn't like. It's sloppy when you don't remember what you talked about last time. And it makes a very good impression when you can cite details of previous conversations and address her in a way that she appreciates. You can try to remember everything, but it is probably better to write it down so that you can read it again before the next appointment and prepare well for the interview or appointment. No one can remember everything, don't try that, but teach yourself to write a short report for yourself after every conversation or appointment.
Maintaining contacts, especially business contacts, is not something that goes by itself. Also in business contacts there are certain (unwritten) rules to appeal to people. More on that later. If you have a business, maintaining contacts and engaging in new contacts is probably the most important activity to be successful. Knowing your customers, understanding what they need, gaining the trust of your customers. This is all part of establishing and maintaining contacts.
As we wrote before, don't try to remember everything, but write it down. Make sure you instruct yourself to write down what you have discussed, what you have agreed (confirm that by email to your interlocutor) and what you have observed immediately after each conversation or meeting. Then you can read that again next time before the interview or appointment.
You will see that if you do that consistently, always follow up the contacts on time and can cite what you have discussed next time, your interlocutor will appreciate that. This builds a good relationship with your contact, and that is essential in maintaining contacts.