Why do guys set up a date and then cancel it?

Alright, I met this guy on the Internet, then there were tonns of texts, several phone calls from him, he set up the date, then cancelled over text, saying that he had to bring his mom to his sick uncle. It was an emotionally intense experience - the one that lead me believe him and hope that we might get on just fine. A lot of words on his side lead me to think he really wants to meet me. Then on the day when he cancelled, in fairness, he called, texted and asked if I was around on Sunday. I replied (a bit later, of course) that fine, I understand and "not sure what I do on Sunday", then I asked when do you want to meet - nothing still, no response. We were meant to meet last night and the guy dissappeared. What on earth happened? Why all this attention, sending of photos, compliments, texts, calls - all for nothing? Any insights about it?