Dremels are like talking about living in CA or FL. You either hate it or love it.
I got my 1st rotary tool (Sears L'il Crafty, still have it, & it still works) in the early 1960's, as a kid, to work on slot cars. That was a favorite activity then. I still have friends, when I attend a reunion, mention having fun playing w/my slot cars. The rotary tool was a boon to trying things out, attempting to make mods on the cars, or doing work on the track, scenery and stuff.
As an adult, I bought a Dremel, I think I've owned a half-dozen Dremels, most of them being the rotary tool. I will never be w/o one, because they do what I need, when and where I need to do it. Sure there are much more-expensive rotary tools, which may work better, but for the use I put 'em to, the Dremel works.
I suggest you buy the flex cord and the mandrels to use different diameter shaft accessories. I never use it w/o the flex shaft anymore but I could if I needed to. Swap-over w/o the flex shaft would probably take a minute and a half.
Working on motorcycles, I use 'em for defeating security screws on float bowls (I'm a retro-grouch, no fuel-injection in my 'cheaper-by-the-dozen' stable). As zrx61 said, they are the bee's knees for deposits/oxidation/corrosion removal in small spaces. For the O-ring grooves in calipers, I usually use large brass wire wheels. 'Large' in Dremel-speak, is a 1-1/2" dia. piece.
I just bought a set of cut-off discs, fiber-reinforced, on Amazon, something like 50, and 4 mandrels, for $10. The EZ Lock cut-off discs are what Dremel went to, they're more-expensive than the old style. I have both. The Big Box Store I frequent only has the EZ Lock cut-off discs anymore. The old ones, you could buy in a PEZ dispenser, 20 for something like $35, but I haven't seen those in years at the store.
Wear your eye protection! I cannot emphasize enough how-important this is! If you value your eyesight, you will never be without it. The cut-off discs you want to use are the fiberglass-reinforced ones. Even then, if you place lateral pressure on the disc, it will fragment! The broken pieces are akin to shrapnel, and without eye protection, you could lose your eyesight, one or both, in a worst-case scenario.
Bottom line, you will find many uses for it. If you don't, gift it to someone who can use it.