The past simple without a time expression

Hi. I know that it's possible to use the simple past tense, even if there is no time expression. However, I realise that the action has to be finished in the past. Here I'd like to give you an example, so that you can see what I mean.

- This amazing journey has finished. I learnt so many things. My soul was completely changed. I met plenty of interesting people and bought amazing souvenirs. (I'm using the past simple, because I suppose that all these actions occurred in the past, during the trip, which is finished.)

And here's my question. Should I use the past simple here or the present perfect?

Thanks