One of the primary reasons why people stay addicted for long is to win big. They think a big win will solve financial and all other problems in their lives.
For this very man greed was his problem £20000 is a huge sum that can afford a very lucrative business. Giving such huge amount on gambling shows his high level of greed and people of this kind can do anything just to make money not minding if it's legal or not. I wish he recovers soonest because this can cause a man to commit sucide.
but he regrets this the rest of his life , meaning he is also a small time gambler who only tries his chance of a lifetime but failed . maybe this will be remembered all the moment of his precious life how he managed to lose a amount in which can change his life for goodness if chooses the right decision.
No, he won't regret that for the rest of his life. He will regret it temporarily but he won't bring that forever, he might bring that for a long time but I doubt that he's going to regret that forever.
He's going to remember how reckless he was and that's for sure.