The Washington Capitals’ history of playoff disappointments began even before they ever reached the postseason.

The proof is hanging in the closet in Bruce Peters’ home in Waldorf, Maryland, about 30 miles away from where the Presidents’ Trophy winners will face the Pittsburgh Penguins in Game 7 on Wednesday night with a spot in the Eastern Conference finals at stake.

The T-shirt, purchased at the long-since demolished Capital Centre, remains in impeccable condition. On it is a cartoon image of an unnamed Washington player with a devil sitting over his shoulder. Across the bottom it reads: “Playoffs 1981 — Paid Hell To Get Here.”

One problem. The Capitals didn’t actually make the playoffs that spring, finishing last in the Patrick Division instead.

So much for truth in advertising.

Not that it mattered to Peters. An 8-year-old at the time, he was already hooked on the game and the guys in the red, white and blue sweaters. And he’s stayed that way. Through the Easter Epic and the Stanley Caps. Through Yvon Labre and Rod Langway. Peter Bondra and Olaf Kolzig. Jaromir Jagr (whoops) and Alex Ovechkin. Through Esa Tikkanen’s botched open net in Game 2 of the 1998 Stanley Cup Final. Through blown 3-1 leads and Game 7s that almost always ended with a handshake line as the other guys moved on. Through 43 years and four wins — four — beyond the second round.

So Peters will watch Wednesday night, possibly in person if he can swing it. He will rock the red. And he will believe once more.

“At least the Caps have given you a glimmer of hope, something to root for,” he said. “Whether it be the Presidents’ Trophy or a Game 7 overtime win or whatever.”

He clings to those moments — Dale Hunter’s Game 7 breakaway against Ron Hextall in 1988, or Joel Ward’s winner against Boston in 2012. Finding a way to make the conference finals for just the third time ever at the expense of the Stanley Cup champion and longtime nemesis Penguins — who are 3-0 in winner-take-all games against Washington — would just be the icing.

“The Penguins always seemed to get the bounce,” Peters said.

Wednesday night offers a chance for the bounces to go the other way. If they don’t, all those failures — the ones Peters say “kind of blur together” — will add another painful chapter.

So let’s not miss an opportunity to stick our thumb on the wound just one more time.

THE EASTER EPIC: Technically, Game 7 of the 1987 Patrick Division semifinals began on April 18. It didn’t end until around 2 a.m. on…