I've experienced the highest of highs and lowest of lows. I think to really appreciate anything you have to be at both ends of the spectrum.

It's been a high-low year for me. The highest of highs, the lowest of lows.

I'll tell you, being involved in human space flight, it is an emotional endeavor. I think it brings in the highest highs and the lowest lows.

For me, the best times are always going to be the most intense, the ones with the highest highs and the lowest lows.

To get 50 caps you have to go through highs and lows - and I certainly had a few - it has never been rosy but to be still here, as well as enjoying good times at Celtic is very pleasing.

I think I'm lucky in life and not just in football. I was very fortunate to play for a great organization and a great team that was really good near the end of my career.