The 27-year-old actor finds being a celebrity is alienating because people don't treat him normally anymore but admitted he is happy he didn't become famous sooner.
He told Spain's GQ magazine: "It's strange, you don't have a normal life anymore. You spend much time trying to fight it, but in the end you find another way to live.
"People don't know how lonely you are. In any case, I feel fortunate because success didn't reach me very young, at least, I had the opportunity to have a life before.
"When you become famous, it's easy for some people to hate you just because you are famous. That's why, sometimes, you beat yourself up."
Robert also admitted he was unprepared for the way his life would change after he shot to fame by starring as vampire Edward Cullen in the 'Twilight Saga'.
He said: "I lived in a small apartment when the premiere arrived and didn't even know if the sequels would be made. Then came the weekend of the premiere and it was, ‘Oops, now we must do the sequels.' "
No Irish Need Apply? Not anymore