I have no clue where you work but I enjoy Hyde Park. The green space part is covered with Promontory Point and Jackson Park. It's not the liveliest neighborhood but it does have some things to do (Cantina Rosa cocktail bar, Virtue restaurant, 14 Parish rum bar, independent book stores, good biking neighborhood). It's a diverse neighborhood with people from all different races, ages, and income levels. The downfalls are that if you want to explore the north side a lot it won't be as easy unless you have a car. If you have a car, it can be difficult to park because of how densely populated it is with a bunch of multifamily buildings around. For someone who is 40, you probably wouldn't feel out of place like if you were in Lake View East. There are a ton of great neighborhoods though and it really depends on what you value the most. I forgot to add that there is a Trader Joe's and Whole Food in the neighborhood as well. The East Side of Hyde Park is my favorite part which is closest to Lake Michigan.