Stand in front of your mirror. Look at you. Almost every atom, every quark, every electron, every neutron, proton etc. was "born" many years ago, in temperature reaching millions of millions degrees. Some of theme was thrown out in very big Supernova's explosion. Others was "born" in the quieter parts of Universe- in smaller stars, or in interstellar space.
But let's make our private atom, at the beginning let's make the hydrogen. It's very "simple"- we just need one proton, and one electron. If we don't have any electron, don't worry, just wait. Placing the lonely proton in the space we need only wait until he attracts to himself an electron, attracted by the force of electrostatic interaction. In fact, creating any atomic nucleus, we don't need to worry about the electrons- they always arrive on time. As you can see the connection electrons with atomic nucleus is not difficult. But, the creation of the nucleus (composed of protons and neutron) is much more difficult.
Now let's get a little more sophisticated chemistry, let's build a variety of hydrogen-deuterium. This requires us to join the hydrogen nuclei (protons) electrically neutral neutrons. If we get closer proton and neutron to each other nuclear forces will join them, much stronger than other forces acting in nature (the nuclear forces are very, very, very strong, but they works only for very small distance). If we managed to create deuterium, we can now attach to it the last neutron to form tritium, the heaviest variation of hydrogen.
But, suddenly something fucked up. Our tritium twitched, something very quickly ran out of them, one of the neutrons turn into proton, quickly escaping from the nucleus electron and much faster neutrino. We were now alone, but there is something else! Our tritium was transformed into a helium nucleus. Surprise like that, happens us more than once or twice when we played in the creation of new elements. It wasn't very hard to make tritium- adding neutrons to the nucleus is not very complicated. But, here is another surprise. Lonely neutrons which we want to use to make another nuclei break up very quickly if they're out of the nuclei. So if we want to make another chemical elements, we need to use protons, but! another surprise [sic!]. The addition of a proton, which is positively charged, to the positively charged nucleus is very, very difficult because the same electric charges repel strongly. If we want to break these electric wall we must use very speeding proton, excel at the center of the nucleus and pray for good luck. In the best case, a speeding proton goes in the middle of the nucleus, nuclear forces will work and we get a new nuclei of a new chemical element.
Our Universe was formed 13,8 billions years ago in the sparkle of Big Bang. First nuclei of hydrogen, helium and lithium was "borned" few minutes after Big Bang, when temperatures, density of matter was so high, and protons and neutrons was able to connecting. Universe during the Great Inflation was expanded, temperature dropped down, and almost every matter turned into nuclei of helium, rest has become lonely protons and electrons (the temperature was almost to high to let to connecting between protons and electrons together). When the temperature dropped down a little bit down, electron have been started to reach protons, and then the hydrogen began to gather in great clouds, which then began to collapse, forming stars, which as a fuel for the light used a high temperature to connect the hydrogen into helium. That caused the first stars were very large. When the hydrogen in them were exhausted and remained nearly only helium, the star out of the energy sources began to shrink. The star was shrinking and shrinking and shrinking, until the temperature of the crowd rose again. Helium in the midst of star (in more than one hundred million degrees), were burned very quickly. The result was the rise of burning helium nuclei into carbon, oxygen, neon and magnesium. The star continued to fell, and the temperature rise, coal "burned" at six million degrees, and later at several billions of degrees, until the formation of iron in the core of the star.
Iron nucleus reluctantly joins other nuclei. This process instead of give energy, it absorbs it. The star, who produced the iron in the center, is doomed to death. The star explodes. Star emits into the space created in own middle matter. The exlposion emits neutrino and many neutrons that scattered close to the speed of light speed, collide with the nuclei of other elements, which allows to create elements heavier than iron, such as lead, mercury, uranium, etc. Because these nuclei are joined only neutrons, then must have place a "surprise" that we had when we were playing with tritium- for equilibrium neutron turns into a proton, throwing out of himself and an electron neutrino.
And so in cosmic explosions of stars formed material which we are built. I wonder where in space were "born" elements which build our hand, foot, brain, or eye ...