But the point I am making is do I just nail my colours to the mast at some point and suggest meeting again because I know plenty of women who have done this...and it's worked.
No. Because you risk getting no reply, blocked, a string of excuses where he doesn't tell the truth and you're no further on, or 'whatever are you thinking of my dear, we've met twice'.
If he wants to see you he's got your contact info.
Keep busy, enjoy your hols, put him out of your mind.
Being really, really blunt, he may have had 2nd thoughts about you during the day and not wanted to end it abruptly by saying he'd had a nice day but didn't want to take it further.
ALSO many people doing OLD are seeing several people at once or in succession. Of course he won't tell you that, but each of you are free to date other people and you don't know where you stand in this.
He may have dates lined up or he may have had dates before your walk .
I'm older than you. It's along tie since I dated BUT I have friends who do.
It's very common to say 'I'll call you' or 'Lets do it again' and then be ghosted. This is because a lot of people are afraid to be honest face to face.
In fact 40 years ago a man dropped me off at a bus stop and said 'I'll call you' (after our 2nd date) and I'm still waiting!