(idiomatic) take root, strike root

a root / the source; the root / nature; the character one has by birth

thought / opinion / idea

he / distal demonstrative, something far off removed from both speaker and listener: that / boyfriend

distal demonstrative, something far off removed from both speaker and listener: that, yon / particularly, male personal third person pronoun: he / by extension from he: boyfriend

he; boyfriend

mind, heart, spirit, soul; thoughts, ideas / attention, mind, interest / heart, feelings, emotion, emotional state / wholeheartedness, sincerity, true heart

attach itself to, stick, stick to, adhere, adhere to; be connected with / come in contact with, touch, reach / be attached to, belong to, join, associate with; take up the cause of

gain / become

root / base, foundation