Daniel Reed, 19, was today told he must serve a minimum of 24 years in custody over the murder of 55-year-old Shaun Skelton.
A court heard Reed "loathed" his stepfather and attacked him as he slept on a sofa after forcing his way into his flat in York.
After the killing, the teenager told a doctor that Mr Skelton was "just a waste of space, someone who doesn't deserve life."
Reed armed himself with a hammer and a screwdriver before walking from his mother's home to the property where Skelton lived at Chancery House, Holgate Road.
Reed was caught on a CCTV camera kicking the door down shortly after 11.30pm on March 5 this year.
Jonathan Sharp, prosecuting, said: "The pathological evidence and evidence from the scene show that he engaged in a sustained and frenzied attack on him."
Mr Skelton suffered 70 separate injuries including a skull fracture and a gaping wound to the throat.
It is thought the victim was struck to the head with the hammer at least 15 times and was kicked, punched and stamped upon.
He was also stabbed to the chest and neck area with a knife.
Mr Skelton and Reed's mother had been in a relationship for some time but did not live together.
Mr Sharp said: "Reed loathed him, had said repeatedly to his mother that he wanted to kill him, and had previously attacked him."
Reed said he was "elated" after the killing and described the attack in a letter, stating: "I ran upstairs and kicked his door open, he was asleep and I woke him up. I didn't say anything until I sat down...I smashed his head in with a hammer then I cut his throat...I loved it.
"I had an urge to kill him. I didn't have an urge. I finally did it.
"The feeling of a life in your hands is to save a life, it's the same rush in taking a life. I probably feel better about ending one.
"I can still see his face covered in blood crawling around trying to get up. I told him don't get up, I'll make it easy for you."
The prosecutor said Reed telephoned his friend, Scott Fletcher, after the murder and made arrangements to leave York and go stay with him in Leeds.
Reed stopped at a taxi office on his way to York railway station and asked to use the toilet to clean the blood off himself, claiming he had been punched.
He then said to taxi staff: "I lied, I've slit someone's throat."
After being told about that incident Fletcher's text message response was "LOL, you sick guy delete all messages and phone calls."
Reed approached a man at the railway station and told him about the killing.
Mr Sharp said: "Reed volunteered he had beaten his stepdad up, hit him over the head with a hammer and 'he wouldn't die so I slit his throat'.
"His demeanour was blase and nonchalant."
Reed left the station as there were no trains to Leeds and went to see friends at a hostel to tell them what he had done.
Police arrested Reed at the hostel in the early hours of the morning.
When asked by the officers where he lived, Reed replied: "In a pineapple under the sea."
Reed, of Strensall Road, York, pleaded guilty to murder. Fletcher, 18, of Grantham Towers, Burmantofts, Leeds, pleaded guilty to assisting an offender.
Fletcher will be sentenced later today.
Mr Sharp said Reed had a history of disturbed behaviour since childhood.
He has previous convictions for violence and carrying weapons, including stabbing a a member of staff at a local authority care home with a pair of tweezers.
Reed also has convictions for assaulting police officers.
Sentencing Reed, Mr Justice Langstaff said: "One of the most horrifying aspects of the offence was the way in which afterwards you appeared to glorify what you had done.
"You were not at all remorseful. You are a very dangerous man - as you now are - but you are a very young man."