Christian Perez is a young man who’s clearly capable of embracing change — as evidenced by his bright red Phillies T-shirt with the name and No. 3 of the team’s newest slugger, Bryce Harper. So why did the 30-year-old health-care worker from Philadelphia’s Hunting Park neighborhood just spend a couple of hours on a perfect sun-soaked spring Saturday watching a 76-year-old man — namely Joe Biden — officially kick off his presidential campaign?

“We need unity in this country,” said Perez, as Biden and his wife, Jill, shook hands a few feet away on Eakins Oval and as the distinctive synthesizer riff of the Who’s 1971 classic “Won’t Get Fooled Again” amped up in the background.

“People are looking for electability,” he added. “They want to go back to how it was when President Obama was president. We didn’t have these fears that people have right now” — an allusion to Biden’s comments made moments earlier that President Trump posed a threat to American democracy, “People just want some familiarity.”

Perez couldn’t have said, meet the new boss ... same as the old boss ... any better than Roger Daltrey blaring from the speaker behind him. I’d just spent several hours on the Benjamin Franklin Parkway talking to voters and trying to understand why Barack Obama’s former veep has such a massive lead in the early polls, even though a) 22 other Democrats are running, some of them formidable b) the first caucus is nearly eight months away c) Biden’s two past presidential campaigns (in 1988 and 2008) weren’t even good enough to be called underwhelming.

People said exactly what I expected them to — that the only thing that matters is beating Trump, and they believe no one looks better positioned than Biden to guarantee that happens on Nov. 3, 2020. I was a little surprised, though, by just who was saying that,

For one thing, the decent-but-not-overwhelming crowd (probably not quite the 6,000 estimated by the Biden campaign) for the rally was sprinkled with blacks and Latinos but overwhelmingly white, even though supposedly it’s his edge with non-whites that has Biden so far ahead of rivals like Sens. Bernie Sanders and Elizabeth Warren. But the attendees were also younger than I’d expected, with a decent number of recent college grads and students.

Yasmine Hamou said she’s undecided in the Democratic primary but she sees Biden’s selling point as that he probably appeals to voters NOT like her — a 22-year-old newly minted Temple University grad and a black woman. Hamou — who canvassed a lot of Republican voters when she volunteered for Obama’s campaigns as a high schooler in her native York, Pa. — told me Biden “really can relate to a lot of middle-class white Americans and I think that’s what’s really going to be key in this election.”

But doesn’t she want to be excited by a candidate who’s making more of a pitch to voters like her, especially with so many women in the Democratic race?

Hamou took a deep breath. “Yeah, you give up representation and you give up someone who’s going to more fiercely fight for rights, especially as a woman .... [But] we can’t take huge steps like this, especially when we’re reeling from something like the 2016 election. Going as extreme as possible is not the right way to go.”

A short time later, Biden and his aviator sunglasses bounced onto the stage to Elton John’s “Philadelphia Freedom,” knowing he had a message that this particular crowd wanted to hear. “I believe Democrats want to unify this nation,” he said, nearly washed out in sunshine. “That’s what we’ve always been about. Unity.”

But if you listened more closely to Biden, you could hear the contradictions that may grow louder in the coming months. If the goal of the campaign is national unity, how come the biggest applause lines were his harshest put-downs of Trump, like when he said the booming U.S, economy “was something he inherited ... just like everything else in his life”? And if Biden knows how to cross the aisle and work with the GOP to get things done, then why did he also boast his biggest achievement with Obama was passing the Affordable Care Act — “without any Republican votes!"

Wait, what?

As someone who, by scribbling notes at today’s rally, has now officially covered 10 presidential elections, I wondered if the obsession with “electability” — voting for someone not because he excites you but you think he excites people who aren’t like you — can be a dangerous trap. Just ask Al Gore, John Kerry, and Hillary Clinton — each crowned before they weren’t elected.

Biden’s DJ probably should have ditched the Stevie Wonder for some Ed Sheeran and Taylor Swift, because this was a crowd that clearly wanted to party like it’s 2015, when Obama seemed to have everything under control and Biden was his wingman. A small part of that may be a craving for the center-left politics of the two men. More of it, I think, is a simple dream of a decent human being in the Oval Office again.

But a lot of the craving for 2015 is likely a desire to return to a world where bright May Saturdays were for softball games and cookouts where no one was rolling their eyes over the latest presidential tweet — where for the most part people didn’t think about politics at all. I was struck Saturday by how many people walked out of Biden’s speech before it was even over — praying that their affable Uncle Joe had things under control, and that we don’t get fooled again.