Barnes scored twice and was named man-of-the-match for Sunday's win, which was missed by manager Eddie Howe as he recovered from an illness in hospital.
"It's been a weird week without the gaffer being in," said Barnes.
"We know he wouldn't be missing games if he wasn't seriously ill.
"We went into the game today knowing exactly what we needed to do. It's just his voice and influence that hasn't been there this week."
Barnes continued: "I'm playing with a smile on my face at the minute, enjoying being out there.
"I love playing football, love scoring goals, when you do that you can't help but enjoy it. That was reflected in the team as well. It was a good day at the office."
He added: "We've got ourselves into a great position in the table, but we're just approaching each game as it comes. We know if we go and win our remaining games we will be in the top four."