Some of the cleverest code can be the most hard to read, maintain or debug. Clever code isn't because it's not maintainable and often no fun to work with. No matter how proud you are of your one-liner, or complex system you built... if you can't maintain it, it's not very clever, is it?
Heads up: As with any terse bit of advice, there will be exceptions of course, and subtleties and nuance that can't possibly be captured in a Byte of Wisdom. This has been what I've experienced, I'd love to hear yours in the comments too!