One of the most painful injuries I suffered was in the Sportsground in Galway four years ago when I dislocated my elbow. One minute I'm running around, doing what I'm meant to do, and the next minute I'm on the ground in total agony.
The pain was just unreal. I didn't care about the match, I didn't care about anything. All I wanted was for someone to stop the pain. I was roaring and shouting, the lads gave me a torrid time afterwards about all the squealing I was doing. But I didn't care. I just needed someone to stop the bloody pain.
The medical staff were brilliant and so too were the people in the hospital in Galway. They got me in there, knocked me out with a general anaesthetic, slotted my elbow back into place and the next thing I remember I was waking up and Paul O'Connell was standing beside me with a burger and chips.
The pain was gone and a burger and chips never tasted so good. Paulie always seems to know the right thing to do in a moment. Later that night he drove me home in the car and it was only then that I began to start thinking about the implications.
It will have been that way with Tommy O'Donnell this week. He went into the game knowing he was battling for a place at the World Cup and as the game developed he must have been pleased because he was giving it his best shot.
And then, quick as a flash, his World Cup is finished. He doesn't know yet whether he will need an operation but at best he is looking at five to six months out, maybe even 12 months. That is a huge blow.
I know from my own experience when you have a major injury like I had with my shoulder dislocation, my elbow dislocation and my knee reconstruction, that not alone are you dealing with the specific injury itself but it affects the rest of your body because it stops your ability to keep exercising. Your body, the rest of the muscles, go to sleep so there is a huge amount of work in coming back from a serious injury.
It is not just fixing the knee, rehabbing to build up the muscle in that leg and you are back. There is a major challenge now for the rest of your body to get it back up to speed and to keep the muscles working and keep their strength and their size.
It is a very traumatic injury for Tommy and there is no doubt this week will be mentally very tough for him. He was in extreme pain and to go through that trauma on a rugby field is difficult.
There was obvious shock within the stadium when it happened. He went into the dressing room after it, they tried to put his hip back into place and was in incredible pain.
I believe he was screaming and roaring which is very unpleasant, obviously for Tommy first and foremost but for his team-mates and anyone around. There is a real shock when that happens when someone picks up an injury and they are in that kind of pain. He was brought to hospital then and he was put under anaesthetic and they put his hip back in place.
I was speaking to Tommy about this. You wake up from the anaesthetic and you are like, 'Is this a bad dream'. That is the way you kind of feel.
It is inevitable when you get an injury like that, you become the victim a little bit and that is fully understandable because your emotions are all over the place. Tommy would have worked so long to be in the mix because he wasn't obviously guaranteed his spot. He was fighting tooth and nail to get into that squad and would have worked unbelievably hard the last few months.
I know Tommy a long time, he is from Clanwilliam, my home-town club, and I know how hard he has worked to get this far. But he has a great attitude and he is only 28 and I know he will bounce back.
He is the ultimate professional, always willing to learn, pushing himself harder, continually trying to get better and trying to maximise his talent. I think in the last year or two he has really stepped up another level. He has gone from provincial squad player to provincial starter, to playing for Ireland and having a role with the national squad now.
He was omitted from the squad a few times but any time he has played or been involved he has done really well. When you are on that upward curve of progression it makes it a harder pill to swallow, but he will recover and have better days.
I have an earnest wish that he will become the most-capped Clanwilliam player of all time. He has nine caps, I'm on 27, but I think he will surpass me and I really hope he does.
All eyes will be on the Aviva this afternoon for what is another experimental side against Scotland. This will be the last experimental side, I expect full strength against Wales and England.
There are still positions up for grabs and guys are on trial. Simon Zebo at full-back is interesting one. Joe Schmidt doesn't waste his own time or anyone else's so by putting Zebo at full-back he is saying can you play full-back, prove it to me on Saturday. But it is a positive sign that he is getting a crack there. Gordon D'Arcy is getting an opportunity as well. It's tough to say he is looking for an opportunity considering his experience but that's the way it is. He will be trying to grab a lifeline for the World Cup. He is a little bit behind after the Six Nations.
He really has to perform today. Tommy Bowe needs game-time. Jared Payne and Luke Fitzgerald are on the plane but also need a run-out, and with Ian Madigan at 10, it is roles reversed this week. He is getting a crack to see who will be back-up to Johnny Sexton. Isaac Boss also needs game-time.
It's a difficult one for Dave Kilcoyne. If Cian Healy is fit he's not going and vice versa. It is a catch 22 for him. Michael Bent has the versatility to cover both sides so it is tough on Kilcoyne. But he has to go out and give Schmidt a headache and make it difficult. It is a tough one because it is very, very competitive area.
There won't be many chances for players after this one so they have to make the most of it. And hopefully everyone comes through unscathed.
There are 160 minutes of playing time left to impress Joe Schmidt and, with more changes expected in two weeks' time, no guarantee of a second chance, so for the Ireland players this afternoon it is all about seizing chances.