Former Wigan Athletic hero Will Grigg admits it will take time to process 'the first time I've fallen short' in League One.
Grigg left Latics in a beat-the-deadline move in January, with Sunderland paying £4million to take him to Wearside.
Having won promotion from the third tier, and passing the 20-goal mark, on an incredible FOUR previous occasions - twice with Latics - Grigg and Sunderland tasted defeat in last weekend's play-off final to Charlton.
And he acknowledges it's a strange feeling not to be celebrating promotion at the end of a campaign.
"There's disappointment and everyone will have their time to get their heads round it, get the emotions out the way," Grigg said.
"We'll back in probably four weeks and it'll be back to business, trying to rectify and put everything right.
"For me personally, it will be about getting a good pre-season and hitting the ground running.
"This is the first time I've fallen short in this league.
"It's been a disappointing season for myself, and I want to make sure it doesn't happen again next season."
Grigg struggled to find his best form in a Sunderland shirt, having been carrying a leg injury - sustained in his last Latics appearance at Sheffield Wednesday in January - when he made the move north.
He only came on for the last half-hour at Wembley last Sunday, and was powerless to prevent the Addicks - including his ex-Latics colleague Jason Pearce - scoring a stoppage-time winner.
For a Sunderland side tipped by many to go up automatically last summer, it represented a massive collective disappointment.
Typically, though, Grigg refused to sugar-coat the situation.
"At the end of the day, we haven't been good enough over the season to get ourselves promoted, it's as simple as that," he told the Sunderland Echo, sister paper of the Wigan Post.
"Too many draws, too many leads lost, not enough clean sheets.
"I'm sure people will say not enough goals scored as well.
"It's one of those things, you lose as a team, you have to defend from the front, it's not about pointing fingers at strikers or defenders.
"We haven't been good enough as a squad.
"We're not a bad side but we're not a great side.
"We've done all right, but it's just those little bits here and there, that little bit of quality in the final third or shutting up shop at the back."