I have never discovered a penicillin, and I have not worked in the mines where ores of the more Nobeliferous metals are to be found.
The only reason we don't notice how absolutely interwoven our thinking processes have become with older technologies - pencils, paper, electric light, penicillin, fire - is that they're old, so we've ceased to notice their effects.
Long lives aren't natural. We forget that senior citizens are as much an invention as toasters or penicillin.
Prior to penicillin and medical research, death was an everyday occurrence. It was intimate.
Once you have speech, you don't have to wait for natural selection! If you want more strength, you build a stealth bomber; if you don't like bacteria, you invent penicillin; if you want to communicate faster, you invent the Internet. Once speech evolved, all of human life changed.
If we stop exploring space, we're going to lose the same part of us that found vaccines and penicillin, the part that searches for cures to cancer and AIDS.
If they can make penicillin out of mouldy bread, they can sure make something out of you.
Perhaps the most useful lesson which has come out of the work on penicillin has been the demonstration that success in this field depends on the development and coordinated use of technical methods.