The author argues that Szymanowski's famous statement about his First Symphony Op. 15 (1906-1907), which disappeared from the concert programmes after its first performance in 1909 and remained unpublished to this day, should not be taken too literally and that the symphony deserves more attention that it has received up to now. The symphony is analyzed from the perspective of Polish and German symphonic traditions and some of its distinctive features are discussed. The author questions the 'Straussian' label given to the main theme of the first movement set in sonata form and fast tempo, demonstrating that its chromatised structure with dark harmonic and timbral tones resembles more the 'King Roger' than the triadic 'Don Quixote' theme. Although the impact of the 'New German' school cannot be denied, several features distinguish the symphony from these models; the whole concept of the work and such elements as occurences of clear tonality and unexpected cuts, typical of Polish symphonic style, especially of Szymanowski's teacher Zygmunt Noskowski, and the placement of the climax, marked by a whole-tone chord (rather unfamiliar to Wagner and quite popular among the 'Young Poland' composers), in the second part of the development. The author demonstrates that in his First Symphony Szymanowski, already at that early age experimenting with the most radical consequences of contemporary stylistic trends makes an important step towards a new individual symphonic idiom beyond conventions, with a harmonic languages much more modern than that of any other Polish composer of the time, and structure close to the Adorno's 'total development' principle of the Second Viennese School.