Why when I was 5 years old did I rip things apart in half... Always trying to get another half... is it endless?
I took a leaf and ripped it in half, and kept on going...
Electrons are fundamental. They have no internal components, no building blocks. They are point particles, they have infinitesimally small size. There are other fundamental particles. These are the quarks, the other leptons (muon and tau), the neutrinos, gauge bosons, and the Higgs boson.
There are some hypotheses that claim the particles listed above are not fundamental and are composed of smaller components, but none have been confirmed. One prominent such hypothesis is string theory, which proposes that all of these particles are composed of a kind of 1 dimensional string vibrating in 10+ dimensions.