wouldn't diminish your background either, but I don't think our positions are as similar as you suggest. You were fortunate enough to have a home. I was not. That's quite a major difference and influence on our motivations and behaviour. Even if you didn't mean it, framing our positions as similar plays down that difference.
And education wasn't "free". Unlike you, I was just caught by the introduction of tuition fees. My parents also paid taxes towards it, as do I and my family. Calling it good fortune overlooks that it was paid for by workers, and ignores the fact that graduates have traditionally generated more tax for the economy. You say we shouldn't put everything down to privilege, but the rest of your reply leans heavily that way: your own success is put down to luck, and the case for IHT rests on undeserving heirs. So I'm not sure that concession goes quite as far as it seems.
If it doesn't matter to the dead, then why do people make wills? Because they care what happens after they die. It's my money, and it's already been taxed. I should be able to decide whether to spend it all today or leave it for my children to spend. Why should the timeframe I choose dictate whether it's taxed again? I wouldn't object to a modest tax on any genuine windfall gain on my house, after my costs when I sell it. But that's very different from taxing again everything I've already paid tax on.
@BIossomtoes you are correct I will spend it but @1dayatatime is more correct on my behaviour if I am forced to choose between spending it or losing it. So logically, I will use it, by stepping back early from the labour market. I don't have a huge private pension, but I can make it stretch. The Treasury will still collect VAT on what I spend, but that won't replace the PAYE and NI it loses. If I'm looking for investment growth to supplement my income, because I am no longer receiving a full time salary, other countries offer better opportunities. Sure, the UK will get tax on the returns, but most of that money will be funding growth elsewhere. People in my position will travel more, volunteer less and give less in general.
You say the system rewards people who don't "deserve" it, and that it smarts when the taxpayer plugs the gap. I agree, and I'd add it also smarts when it rewards politicians for not doing the right thing and expects taxpayers to keep paying for it. I'd also point you in the direction of William Beveridge, hardly a free-market acolyte:
"The State in organising security should not stifle incentive, opportunity, responsibility; in establishing a national minimum, it should leave room and encouragement for voluntary action by each individual to provide more than that minimum for himself and his family."
So if we as a country need to go back to core values, I'd argue my mindset is more aligned with the founding principles of the welfare state.