thoughtful

deep in thought

trying to be like another

simulated, unoriginal

seriously thoughtful

meditative, solemn

deep (the usual word); showing, having great knowledge

intellectual, thoughtful

(of a person) able to think and reason; (of behaviour, a discussion, idea) sensible; reasonable

realistic; of sound mind

sensible; fair; of an acceptable standard or level

moderate, tolerable

looking back on past events etc; (of a law, payment etc) applying to the past

backward-looking

(an animal) that ruminates, e.g. a cow

contemplative

(of) a wise and experienced man; a plant with dull greyish-green leaves, used as a herb

wise

thoughtful; not funny, silly or for pleasure; important because of danger; committed; sincere

somber, humorless

serious and sincere; done formally and with ceremony; serious and not smiling

quiet, serious

enjoying and wanting to study; very careful

scholarly, attentive

having or showing experience, knowledge, good judgement etc

intelligent, reasonable

sad and wishing for something; having, showing disappointment

daydreaming, longing