I'm not Uncle Nick (and I agree that his posts are among the most informative to be found here), but I don't think I qualify as a "poser" either. In addition to being a shooter who has at times been in indoor ranges 4 or 5 times a week for several months out of the year, I'm also a scientist who works in the field of human health risk assessment and I've taken some time to become familiar with some of the primary literature on the health effects of lead. And I also have some personal experience with lead poisoning, in my case a serum lead level of 26 mcg/dl, nearly triple the high end of what's considered normal for an adult in the US, which I've been able to get back to normal levels through religious use of a good-quality respirator.
You've received some good advice about the potential hazards of shooting in an enclosed space, whether that space be your own basement or elsewhere. You can ignore it (but why ask in the first place?), or you can consider the risks and act accordingly. If you shoot more than occasionally in your basement, particularly if you shoot larger calibers, you will accumulate airborne lead in your body and lead residue will accumulate in your basement where it will pose a potential risk to you and your family and possibly others. The effects of lead on the human body are well-known and well-documented.
Now, does that mean you're going to drop dead, or even experience minor health problems from your lead poisoning? Not necessarily - living systems are inherently stochastic and you could be one of those who are particularly tolerant (or, or on the other hand, you could be particularly sensitive). We all know smokers who live with their pack-a-day habit well into their 80s, but that doesn't mean that the risks of smoking are all hype and a wise person would not assume that he could be so fortunate. Similarly, we all know shooters who violate basic rules of gun safety and haven't (yet) injured themselves or others. That doesn't mean the rules are not appropriate, nor that they can be ignored with impunity. A prudent course of action is to assume that the worst can/will happen and act accordingly.
My advice, for what it's worth, is to do what I do - get a good air pistol for shooting in your own basement and save the "real" ammunition for established indoor ranges and outdoors. Alternatively, at least consider wearing a half-face respirator with P100 filters when you shoot in your basement. But, only you can decide for yourself what your own risk profile will be and you're obviously free to act as though the whole lead thing is a scam. Most of us do "risky" things that we enjoy, recognizing that, for us anyway, the benefits outweigh the risks. That's perfectly rational - what's not rational is pretending that those risks don't exist.
And that, I'm afraid, probably makes me an old curmudgeon as well.