A Tool fan in the US might be regretting his decisions right now, having unwittingly asked rock icon Eddie Van Halen to take his picture at a recent concert.

Anyone in the world will tell you that one of the most disappointing feelings is that of FOMO. That is, the “fear of missing out”, or the regret of having not taken an opportunity when it arose.

Music fans have seen it with amazing lineups at gigs, and one famous festival fan would have felt it after members of Them Crooked Vultures posed with his passed-out body a few years back.

However, one Tool fan might just be the latest music-lover to be on the receiving end of FOMO, having unwittingly asked music icon Eddie Van Halen to take his picture overnight.

With Tool currently in the midst of a US tour, the group hit up Los Angeles’ Staples Center on Monday night to deliver a typically-stunning set. With it serving as their first show in the city since 2010, fans from all walks of life came out of the woodwork to attend, including, none other than Eddie Van Halen.

Taking to Instagram earlier today, Wolfgang Van Halen shared an image of his dad taking a picture of a Tool fan, accompanying with it a humorous story.

“A guy asked my dad if he could take a picture of him with the stage behind him, having no idea who he just asked, and that was my favorite moment from the #Tool show last night.”

Check out Eddie Van Halen at the Tool concert:

While this story would have been ever more hilarious if the fan in question had been wearing a Van Halen shirt, this news comes just days after the revelation that the guitar icon has been battling cancer for a number of years.

After David Lee Roth reportedly told fans that “Van Halen is finished” earlier this month, Toto guitarist Steve Lukather clarified that the band were actually on hiatus due to a number of “health issues”.

Days later, it was confirmed that Eddie Van Halen is indeed in the midst of a health battle, having been flying between the United States and Germany for close to five years as he battles throat cancer.

Despite having been given the all-clear from his tongue cancer diagnosis of the early ’00s, the guitarist has been keeping the disease “in check” with radiation therapy, though doctors had removed cancerous cells from the rocker’s throat over the past two decades

Having opened up about cancer battles in the past, Van Halen mused that the disease may have originated from his unconventional usage of metal guitar picks.

“I used metal [guitar] picks – they’re brass and copper – which I always held in my mouth, in the exact place where I got the tongue cancer,” he explained. “Plus, I basically live in a recording studio that’s filled with electromagnetic energy. So that’s one theory.”

“I mean, I was smoking and doing a lot of drugs and a lot of everything,” he continued, “but at the same time, my lungs are totally clear. This is just my own theory, but the doctors say it’s possible.”

While we’re hoping that Eddie Van Halen makes a full recovery in the near future, it looks as though this recent encounter at a Tool gig may have at least put a smile on his dial.

Check out ‘Jump’ by Van Halen: