We all have hundreds, sometimes thousands, of contacts in our phone book but in reality we rarely call nor are called by 90% of our contacts. If you check, you may discover that you never had a single call with some of them right from when you saved the number. If your phone has limited memory, these redundant contacts invariably drain scarce space for more important data.

My question is: are you aware of these redundancies and how often do you clean them up? I just cleaned up mine, though.

I have 1TB of memory on my phone

I save the numbers only of my closest people that I really call often. I use the Telephone directory to call other people and easily find their contacts. And to know who is calling me and whether I should answer, I connected a paid number identification service. So, you know which numbers of your friends and relatives you should save. If you don't want your contacts permanently stored on your phone, if you don't have enough memory, you can download them to google drive, and so it'll be easier to transfer contacts to another device.

I fear u o, to save phone contact 1 terabyte??

Alsonjecs:
I have 1TB of memory on my phone