Most modern writers of Plastic Man follow his portrayal in Phil Foglio's post-Crisis Plastic Man miniseries, styling Plas as a superpowered Jim Carrey on double espressos, his perceptions warped by his odd powers.
That's one way to go with the character, but it certainly wasn't the way Plas's creator, Jack Cole, went. The Golden Age Plas himself was almost never intentionally humorous (forgoing even the usual punnage typical of his contemporary heroes). Although his situations, powers, and supporting cast were exceedingly wacky, Plastic Man was pretty much the 'straight man' in his own adventures. Perhaps that's why Plastic Man was so much funnier then than he is now.
Fortunately, I've discovered what warped the former F.B.I. agent's mind along the way:
Just get Eel to rehab and some NA meetings and I'm sure he'll be back to his Golden Age self in no time!
Oh, and this panel also lends support to my theory that in the Golden and Silver Ages, writers had access to MUCH more powerful drugs than they do today.
Do you have the creativity to haiku in response to Plas's reefer madness ... without resorting to wacky weed?