I’m surprised and slightly disappointed that my memories don’t bring up a clear answer to this.
The hardest problems I’ve faced were never exactly solved, just moved past or muddled through. Things like loss of close friends and family, acknowledging my own limitations, and accepting the inertia of flawed institutions.
Any problem that eventually found a solution I remember as feeling relatively simple in retrospect.
Agreed on the technical problems- the "hard" problems in my career have been massive degradations/failures with no error messages, which are typically solved with liberal application of strace, gdb/pdb, iproute2/ss and Wireshark. Once you find the smoking gun in the kernel or on the wire then it becomes simple again.
I guess the hardest problems I've ever "solved" (mitigated) were mental (depression/anxiety/impostor syndrome). But those aren't one and done happy endings- they're a bundle of general anxieties that are never fully resolved. You just learn how to manage.
Finding a solvable hard problem is itself very difficult. If the problem is within your confort zone, you will never feel that is an hard problem. If it is too far from your confort zone you will not be able to solve it.
The hardest problems I’ve faced were never exactly solved, just moved past or muddled through. Things like loss of close friends and family, acknowledging my own limitations, and accepting the inertia of flawed institutions.
Any problem that eventually found a solution I remember as feeling relatively simple in retrospect.