I will start first

• I didn’t notice my diy NAS motherboard had Pci-E Gen 2.0 (old gen) before buying it. It’s not a great limitation (still 500MB/s) for the two spinning disks I have on it, but it’d be if I will decide to switch to SSDs
• I cheaped out on the PSU. I bought another one without waiting for that crap to burn down so I eventually spent more
• I often break the software. Sometimes I kill the OS or mess with some BTRFS pools

Sometimes I just feel not adequate for it. Does this kind of things happen to you too?