I admit to being old (UR class of 1976). The fact I don't care for the NBA doesn't make me grumpy. I just don't like it. I don't like peas either, or green beans, or sprouts, or seafood, fruity beer, hip-hop music, Star Wars, Marvel/animated movies, VCU, Duke and the SEC, among other things.
I'm actually a pretty happy guy. I've got my health, I laugh all the time, my family is great, my siblings are still alive and kicking, our son is doing great living in a super city (Denver), our house is paid for, I've got a part-time job I love in retirement, I live in a great community in a solidly-blue state, Pika is returning to campus, and I'm far enough away from Richmond that losing basketball games doesn't drive me batshit crazy like some people who live closer and have more invested.
Not liking the NBA doesn't make one old and grumpy any more than liking the NBA makes one young and stupid.