Ride on others coat tails, stand on others' shoulders. It's not that it's any harder, it's that the skills used day to day are different. The single skill I picked up that served me best was being able to rationalize about what complex , highly concurrent code was doing and the performance implications of it. And I got this by reading code, and not just little programs, but things like the udp packet handling in the Linux kernel, or the storage and firewall rule insertion mechanisms for iptables.
But, nothing beats working directly with geniuses. Earlier this year I made a change (at my last company) that increased the number of simultaneous users by well over an order of magnitude. The change was known and had been tried by others in the group, but was deemed infeasible. I didn't come up with the magic change needed, I found how to apply it. And what I learned in the process is applicable outside of that. Without working directly solving the problems, it's hard to learn how.
But, nothing beats working directly with geniuses. Earlier this year I made a change (at my last company) that increased the number of simultaneous users by well over an order of magnitude. The change was known and had been tried by others in the group, but was deemed infeasible. I didn't come up with the magic change needed, I found how to apply it. And what I learned in the process is applicable outside of that. Without working directly solving the problems, it's hard to learn how.