There is an increasing recognition regarding of the importance of introducing modern Einsteinian concepts early in science education. This study investigates the efficacy of an innovative educational programme "Einstein-First", which focuses on teaching Einsteinian physics at an earlier age than usual through the incorporation of appropriate hands-on activities. This paper presents an analysis of 14 to 15-year-old students' conceptualisation of Einsteinian physics and their attitudes towards science as a result of this programme. We have investigated the students' understanding of modern physics concept after a term of 20 lessons. We report on two such 20-lesson programmes, one delivered in 2013 and a second, improved programme delivered in 2014; each to 50-60 students across two classes designated by the participating high school as "academically talented" students. We found, as expected, that the students' possessed little prior knowledge of Einsteinian physics. the significant improvement in the students' knowledge, as tested before and after the course, showed that they could comprehend Einsteinian physics at the level it was given. The findings also showed that the short programme improved students' attitude towards physics.While the male students initially showed greater interest in physics compared to their female counterparts, the female students showed a significantly increased interest in physics after the programme. Also, students' memory retention of Einsteinian physics concepts was tested in two different years, one class was tested after one year of the programmes and the other was tested after three years of the programme. The results show that the Einstein-First programme had a lasting impact on the students involved in the study.