Sure. I use it as a structured place to keep notes on anything that may be important later, not specifically tasks:

• Important people in my life (friends and family) with a short bio, where we met, favorite food, allergies, ideas what I could get them for their birthdays, links to their social media profiles, plans for shared vacations, maybe a few photos.
• Recipes from all kinds of sources. If they are from a video or one of those “scroll past three pages of sentimental nonsense” sites, I summarize them and translate them into German with metric units.
• Lists with interesting links about 3D printing, software development and so on. Keeping these in a wiki instead of just my browser’s bookmarks list allows me to better categorize them and add notes.
• A list of open questions and project ideas that I can’t research right now like “Where is the best place to get custom printed LEGO minifigs?” and “Why do the zfs drives in my home server sometimes have problems waking up from sleep?”
• Lists of interesting products/books/movies/… that I might buy/read/watch/… at some point
• Some writing stuff: D&D campaigns, short stories, diary-like entries
• A list of all computers in my household with hardware specs, operating system and so on

All of those get put into categories and the categories are displayed on the main page via the categorytree plugin. The nice thing about having a wiki is that you have a lot of options for linking or embedding related content while still keeping it somewhat organized.