Nice tribute from a son who is obviously proud of his dad (although I'm a bit concerned about the lack of high-viz jackets - here in the UK the H&S police would have shot them for that).
I had a few moments when I very nearly quit training, and I'm so glad I didn't. Until recently I'd also have said "never give up", "follow your dreams", "you don't want to look back in twenty years and think what if" etc, etc. However, having been through commercial training and made it to an airline, I can now see it's not quite as simple as that.
To be blunt, some people are just not cut out to be commercial pilots. If they realise it at all, it will probably be at the third or fourth CPL or IR attempt, when they're bleeding cash and are too committed to back out. Assuming they don't run out of money, a future of SSTRs and pay to fly schemes beckons. And even if you are the best pilot in the world, your chances of success are scarily dependent on economic timing. I qualified at the peak of the job market and had two airline interviews and a job within three months. If I'd qualified a few months later, I'd still be looking now . . .
By all means go for it, it really is the best job in the world (more a way of life than a job) but for God's sake be realistic about what you're getting into. Don't listen to flying schools' spin, get independent aptitude testing before you start training, and never underestimate the importance of qualifying when the job market is good. Right now it's terrible, and those guys who were in training when the economy went pop have my deepest sympathy.