'Boo-Boys Spurred Us On'
The players produced a rousing second-half display after being jeered off the pitch at half-time.
Speaking to the NEP, Clingan admitted that reaction helped provoke a response from Forest's misfiring players, who produced an outstanding second-half performance to blow Swansea away.
He said: 'The boys weren't happy and the fans weren't happy either - rightly so.
'We didn't do ourselves justice in the first half - but when we went a goal ahead, the fans were like an extra man.
'All the boys were down at half-time. We knew we didn't perform to the best of our abilities and we came out in the second half and proved what sort of side we are.
'In the first half our tempo was a bit slow, but we upped that, got our goal early and went on from there.
'There is a lot of quality in the team. We've been creating chances recently, but not getting the rub of the green, so it was good to get the three goals.
'We came out in the second half, showed how close we are as a team and the crowd got on our side.'
Clingan now heads off on international duty with Northern Ireland for European Championship qualifiers with Denmark and Latvia.
He admits he will have it all to do to get back into the side when he returns from serving his country.
'Every time I come back I seem to be on the bench,' he said. 'Hopefully, this time, I will be able to force my way back in.
'I've been playing in the centre of midfield, which is my best position. It's helped me improve - it always helps when you play week in, week out - but I know there is a lot more to come from me.
'I don't think I've played to the best of my abilities so far, but I've got to work on that.'