For most Finns (bar the self-employed, business owners, and the very rich) filing taxes is like 15 minutes per year when you want to add some deductions the tax man wouldn't already know about.
It's literally 0 minutes, if you don't have deductions.
When the glass is at 50% capacity, one is making an observation of the state of affairs.
When one says that it is "half full" or "half empty" one is already making it into a statement of belief or opinion that reflects one's inner workings and beliefs.
Whether the glass is half full or half empty is not a fact, it's an opinion. The glass being, say, 45.67% from full capacity is a fact. The glass being emptied right now at 55 millilitres per second or being filled at 45 millilitres per second is a fact.
It might be a fact that two people can have greatly different kinds of opinions from the same facts, but they both still deserve to know the facts.
Whether you consider the glass to be half full or half empty is not a fact. It's an opinion.