My friend's dad is tighter than tight. He's extremely proud of his money-saving ways and thinks everyone else is a mug for not following his lead.
He doesn't like any visitors using his loo, he's on a water meter, so he sends them to the medical centre opposite to use theirs.
A relative did some shopping for him during the first lockdown. He complained that they'd spent too much money, and wanted to know why they hadn't been to half a dozen different shops like he usually does. One shop might have cheaper tea bags but dearer coffee for example. Shopping comes to £19.96, he scrutinises the receipt, grudgingly hands over £20, and asks for his 4p change.
Friend met and married a bloke, turns out he's exactly the same mindset as her dad. We went out for a meal, he told the waiter he wanted separate bills, that's fair enough. Their bill arrived, he scrutinised it carefully, it was £49.80, he handed over £50 and told the waiter not to forget his change.
It's like a game with them, how can I save money today? Unfortunately it seems to have made them suspicious of other people, including friends and relatives, as if everyone else is desperate to rip them off.
Both very wealthy people, but maybe that's how they get wealthy. Save every penny, deny yourself pleasures in life, and watch your bank balance increase.