Though obliged does indicate an obligation I'm not sure Daddy saw the obligation as something he had to do, just something he wanted to do. "Desired to do"would have been more a part of his mettle, as he was always so appreciative of the kindness and generosity of others. Though in fact, most people didn't expect a pay back or a return for the favor. It was just the Hoptown way.
Our friends, the Walkers, heard that our grandson Owen was in his school's chess club. They gave us an exquisite chess set to pass on to Owen as a way to encourage his pursuit of that hobby.
I was definitely "much obliged" and I want Owen to be grateful as well. He never sees them to say thank you so I want to encourage him to write a thank you note. Courtesy is a character trait, I want to instill in him. It's important to learn at an early age to "sip" from a cuppa great-TEA-tude especially when one has been served a large cuppa generous-TEA. (1 Thessalonians 5:18)
Not because "one has to" but because "one wants to."
Whether one chooses to say, "much obliged," thank you very much or just thanks, gratitude is always the right choice!