I've noticed twice now that in situations where someone is reporting past events, they suddenly switch to the present tense for no apparent reason. The first example is from this fairy tale. The second paragraph starts out in the past tense and then turns into the present tense:
Кот ходил, ходил и набрел на избушку. Залез на чердак и полеживает себе. А захочет есть — пойдет в лес, птичек, мышей наловит, наестся досыта — опять на чердак, и горя ему мало!
The second sentence in particular seems to read "He climbed up to the attic, and lies down"! This kind of change in tense is completely inconceivable in English. What motivates it in Russian?
The other example I noticed was in some song lyrics:
Мы встретились в маршрутке (past tense)
Под номером один, едем и молчим. (present tense)
Он говорит - доброе утро, (present tense)
А я не слышу будто. (present tense)
Он сжал мне руку сильно... (past tense)