For about 5 years I had a fish tank in my room and got used to the sound of the pump being on all the time... So when I didn't have one any more, adjusting to no noise was hard. You suddenly hear all the noises that the pump masked. That was 20 years ago now, you think I would have adjusted by now.
Its also a left over from having an AIO where any weird noises can be dangerous. With air, its just annoying, as a fan dying is far easier to cope with than a AIO pump. Cheaper too, especially now I have spare fans that I could use for most slots. I think I have codes for a replacement for the 140mm fan in my cooler, the rear 120mm can be any fan.
A credit I had for buying 3 fans last year ended up making my new GPU cheaper than MSRP in my Country. Bonus
I don't want to think about fans. I currently have 5 Bequiet ones that only get noisy from dust build up. That is generally the only noise you want to hear from fans, squeaks and fans randomly stopping, are not things you want from fans. The last few years I have seen/heard it all.
I really have to listen hard to hear my PC now. RGB is the only indication its alive. Even standing right next to it, I can bearly hear it... mainly as I have cleaned its fans twice in recent days and its only 16c outside as its been raining all day. Last night it was about 5c or so warmer than it is now.