Why do I get attached.

First off my original post got taken down due to poor photo which I'm surprised about due to terrible photos on here.

I am currently playing a journeyman save which after a good few years saw me take over Bodo glimt. They finished 4th the previous season, looked like the previous manager played 3 at the back and they had a very tired/slow defence. I sold there slowest center backs and payed a record breaking 4.7mil on a 17 year old, left footed, Perfectionist Norwegian CB. First season we stormed the league, won the Norwegian cup and finished top of the Europa league table. The 17 year old made his first 5 caps for Norway after a great season (baring in mind Ajer is still there) he's now 18 and the German teams are sniffing around offering 8 and then 9 million for him. He wants to leave, I don't want him to leave. We have 4 million in the bank and I told him I'll let him go for 12 million. Annoying because I had to sell their 19 year old goalkeeper I inherited for 650k to the Germans and now he's worth 9 mill and Norway's number 1.