....as well as a true time lord, who seems to have done it all himself at one time or another!
Look...Up in the Sky!
Clark really did love Lois...so much so that he was willing to change the course of time for her (yes, it was a bit odd, and a bit confusing, and they even joked about it in the 100th episode of Smallville, but...take the symbolism that Superman was a hero willing to do anything to save the lady he loved....and let it stand as the expression of Clark's heartache at losing someone and being willing to do anything to get her back).
Beam Me Up, Scotty!
Dr. McCoy gets lost in the Depression Era thanks to an accidental overdose and beaming down to the planet with the Guardian of Forever, and makes a change in history that changes everything in the Star Trek universe in the episode "The City On The Edge of Forever" from April 6, 1967 (written by Harlan Ellison). Kirk and Spock go to set things right...and learn that "Edith Keeler Must Die!". Sadder still, is that Captain James T. Kirk has fallen in love with her.... Not all time travel stories have a happy ending, but this is always considered one of Star Trek's greatest episodes (and one of the best hours of TV).
Trust Me, I'm The Doctor
After all, with 50 years of TV episodes of Doctor Who, 11 lifetimes and countless companions, the Doctor is someone who knows what he's doing right?
Well, not so much.
His time travel device, the TARDIS (for Time and Relative Dimension In Space) is broken (stuck looking like a blue Police Box), and the Doctor has had his heart broken as well.
One would hope so, though, with the price one might pay because of time travel, one never knows...not just because he's alien, or because he's in charge, but because unlike Superman or Kirk, one never really knows what the Doctor will do...