The second-row was one of 15 Welshmen, and five from the Liberty Stadium, named in Warren Gatland's squad on Tuesday.
But despite being hotly tipped to tour, Evans was a bag of nerves in the build-up to the announcement.
"I wasn't that nervous until I went training on Monday and everyone kept on about it. After that, I was just counting the clock down," said Evans.
"I was hoping I could sleep through it, but it was one of the worst nights I have ever had.
"I am normally not the best sleeper before games, but this was horrendous.
"I suppose that is because of all the hard work that has been put into coming back from injury as well as the fact that the Lions only comes around once every four years.
"It is a once-in-a-lifetime opportunity and to be part of it is overwhelming.
"We had a day off yesterday so it was just me, the television and the dog barking at the postman.
"Then at 11 o'clock, it was head down hoping my name was going to be called out.
"When it was, it was just a massive pressure release. I had been so nervous, winding myself up about it, it was wow, and then moments later there were texts and phone calls coming through. It was overwhelming."
But with an impressive strength in depth throughout the squad, Evans is well aware that the hard work starts now in his quest to earn Test selection.
Alun Wyn Jones, Paul O'Connell, Richie Gray and Geoff Parling are the other specialist second-rows named in Gatland's squad.
"Looking at the squad it is full of players who are in form and have proven themselves at the top level," added Evans.
"We have huge depth in the squad and have quality players on the reserve list as well. We have to be confident we can go out there and do a job."